Missing cylinders during idle

[spikeygg]

So when my car is idling it sounds like it isn't running on all cylinders and the engine rocks a bit. I'm curious if you guys know of a good way to prove out whether it's the fuel or spark... here's a video I made this morning that shows the sound difference between the left and right exhaust pipes:


https://www.youtube.com/watch?v=JGP0GYeZZMA

[jmettee]

Tell us a little about the engine. Is it stock or does it have cams (i.e. Stage 2 engine)? If it has cams, that sounds normal from what I can tell in the sound coming out of my PC.

Sounds like mine from what I can tell, here's mine after I installed cams:

https://www.youtube.com/watch?v=SRsK4qRRnSk

[spikeygg]

Tell us a little about the engine. Is it stock or does it have cams (i.e. Stage 2 engine)? If it has cams, that sounds normal from what I can tell in the sound coming out of my PC.

Sounds like mine from what I can tell, here's mine after I installed cams:


My car has 9.5:1 pistons and Isky racing cams (102707HP) with SuperTrapp exhaust. Unfortunately, it seems to only be running on 4 of 6 cylinders. Listening to the exhaust pattern of the left exhaust pipe there is only one or two beats while the right side exhaust pipe has a clear three beats. Need to figure out why all cylinders are not firing.

Our cars sound similar... I can't really tell from the video, do you have stock exhaust? My exhaust pipes come directly from each set of three cylinders so I can get a clean sound signal from each bank. If you have a similar setup, I'd love to hear how each side sounds.

[davidc89]

If you have a temperature gun, you can point it at each one of the exhaust tubes on your manifold. If one is colder then all of the others, you will have singled out what cylinder is not firing.

[Citizen]

If you have a temperature gun, you can point it at each one of the exhaust tubes on your manifold. If one is colder then all of the others, you will have singled out what cylinder is not firing.

Or, if you are poor like me, you can check the plugs, like when you're in there anyway to clean them, like during a tune-up. In my case, I found 5 plugs that were very clean, and one fouled. Yep, while I identified the cylinder not firing, I still haven't determined why that particular one got so fouled, and not the others.

...

[content22207_2]

Vacuum test is marginally useful on an odd fire PRV due to the dead space in our firing sequence (needle quivers even on a healthy engine). But engine wide (central vacuum) the needle should only quiver an inch or so. I suppose a vacuum test on each side of the engine independently would be useful to ensure both banks of cylinders are identical. In that respect a PRV will work for you -- there's no crossover in the firing sequence, so you'll be looking at each side of the engine alone.

But even before going that far I would clip a timing light on each wire, next to the plug boot. Every miss I've ever found has been a bad spark plug, usually oil or carbon fouled, but I did manage to melt an entire bank of spark plugs on my DeLorean once when the HVAC vacuum line cracked (driver's side of the engine pulls vacuum from the passenger intake rail):

44215

In fact it might not be a bad idea to pull all the plugs for a visual inspection . Short of pulling the heads off, spark plugs are the only visual evidence of what's going on inside your cylinders. But a timing light is by far the fastest and easiest way to ensure the plugs are firing. Note that a bad spark plug wire can also prevent a plug from firing (carbon fiber plug wires are bad about fatigue breaking). A crack in the insulation jacket can allow the wire to short circuit to the block. And of course you could have a problem with a terminal inside the distributor cap itself (or simply a plug wire that has come unseated -- our vintage style terminals don't hold on as securely as later HEI terminals).

If all your plugs are firing, pull the injectors to ensure they are all spraying equally and adequately. A weakness of multiport injection is one cylinder's injector can be spraying differently than all the others, causing behavior issues in that cylinder alone.

Bill Robertson
#5939

[spikeygg]

Thanks guys this is helpful information. If I want to pull the plugs I'm guessing that I will need to pull the fuel distributor thingie, is there a how to on that somewhere so I know what to expect? How should I go about clipping a timing light onto all cylinders spark plug wires, those front-most plugs seem to be buried...

[spikeygg]

If you have a temperature gun, you can point it at each one of the exhaust tubes on your manifold. If one is colder then all of the others, you will have singled out what cylinder is not firing.

This is a fantastic idea. I'll definitely try it when I get a chance.

[content22207_2]

Use a 12" extension to remove the spark plugs with the intake manifold in place:

44216

Concerning Cylinder #4: the only reason the idle speed motor is attached to the intake manifold is to facilitate assembly line manufacture (so the engine can easily be dropped into a moving car). When I was K-Jet I relocated my Aux Air Valve to the driver side pontoon and connected it with long hoses (my Aux Air Valve was an electric solenoid, not thermal). Makes engine access much easier. especially Cylinder #4. Also makes fuel/air mixture unit removal/installation much easier.

Bill Robertson
#5939

[Bitsyncmaster]

One thing I found when updating my ignition ECU was I needed to add a capacitor at the 12 volt power input to the ECU to stop a miss fire.

Use a 1000 uf 16 volt or higher voltage as close to the ECU as possible. The negative side of the cap should got to the ECU ground wire.

[David T]

Since your motor is no longer stock you should start at the beginning. I would do a compression test and leak-down test to make sure each cylinder is working well mechanically. Also worth checking valve adjustments. Then you can go on to checking spark and fuel to each cylinder. A vacuum leak can also cause a misfire to the cylinder closest to the vacuum leak so you must check for vacuum leaks too.

[jmettee]

Our cars sound similar... I can't really tell from the video, do you have stock exhaust? My exhaust pipes come directly from each set of three cylinders so I can get a clean sound signal from each bank. If you have a similar setup, I'd love to hear how each side sounds.

OK, knowing you have a non-combined exhaust helps. From the PC, it does sort of sound like your left side may have a miss, but I can tell exactly in the video.

My exhaust is like stock with a 1 in/2 out muffler. That video I posted was without the muffler, but still had the exhaust manifolds & crossover pipe installed, to both sides of the engine were still tied together in that video.

Like others have mentioned, try pulling the plugs or perhaps try the infrared thermometer to try to locate the bad cylinder. With a long extension ,you should be able to get all 6 plugs out without removing anything other than the air filter housing. The fuel injection & idle speed motor always stay in place on my engine when I remove the plugs.

[spikeygg]

Concerning Cylinder #4: the only reason the idle speed motor is attached to the intake manifold is to facilitate assembly line manufacture (so the engine can easily be dropped into a moving car). When I was K-Jet I relocated my Aux Air Valve to the driver side pontoon and connected it with long hoses (my Aux Air Valve was an electric solenoid, not thermal). Makes engine access much easier. especially Cylinder #4. Also makes fuel/air mixture unit removal/installation much easier.

What is the pontoon? This sounds like a good mod to make things more accessible. I don't know enough about it but your statement about the electric vs. thermal solenoid makes me wonder if this isn't something that I can do...

[spikeygg]

Since your motor is no longer stock you should start at the beginning. I would do a compression test and leak-down test to make sure each cylinder is working well mechanically. Also worth checking valve adjustments. Then you can go on to checking spark and fuel to each cylinder. A vacuum leak can also cause a misfire to the cylinder closest to the vacuum leak so you must check for vacuum leaks too.

I have a compression tester, since the plugs are accessible without removing stuff I will attempt that. I don't have a leak-down tester, unfortunately. I found a vacuum leak in the fuel-mixture adjustment hole which I plugged with an extra vacuum plug I had in my garage but how do you propose I detect other vacuum leaks that may exist? On my turbo 3000GT I can plug the intake and pressure test it, is the process similar here?

[David T]

I have a compression tester, since the plugs are accessible without removing stuff I will attempt that. I don't have a leak-down tester, unfortunately. I found a vacuum leak in the fuel-mixture adjustment hole which I plugged with an extra vacuum plug I had in my garage but how do you propose I detect other vacuum leaks that may exist? On my turbo 3000GT I can plug the intake and pressure test it, is the process similar here?

The best way I have found is with a smoke machine. It pressurizes the induction system and makes any leaks visible.

[spikeygg]

Haha, I used the temp gun method of troubleshooting. It works really well, especially on that side since it's very accessible. My measurements look like this after about three minutes of runtime:

Cylinder 6 - 330'F
Cylinder 5 - 180'F
Cylinder 4 - 128'F
Cylinder 3 - 325'F
Cylinder 1&2 - ~315'F (tough to separate these since the header is gnarled in this spot and the starter is in the way)

At this point I think 5 and 4 are out of the loop so I pull cylinder 5's plug, the easy one. It's black:
44222

I use my wire brush on it and a few files to try to revive it a bit, then I have my wife turn the engine over while I watch for sparks to come out the cylinder 5 HT wire. Looks good so I throw the plug back in there and fire it up. Still sounds uneven, probably due to cylinder 4 being dead but I use the temp gun one last time to check the temps on cylinder 5 exhaust and it's HOT, ~325'F. Of course, cylinder 4 was still dead at about 180'F.

Anyway, I tried to figure out how to get to that cylinder 4 HT wire but man it's tight! Any pointers?

Thanks for the help so far crew, we're makin' a dent! :)

[spikeygg]

The best way I have found is with a smoke machine. It pressurizes the induction system and makes any leaks visible.

Smoke machine? Can you post a picture of this thing? I'm not familiar with that, is it like for Halloween? How do you use it to pressurize the induction system? Do you somehow install it just in front of the Air Flow Sensor Plate?

[spikeygg]

One thing I found when updating my ignition ECU was I needed to add a capacitor at the 12 volt power input to the ECU to stop a miss fire.

Use a 1000 uf 16 volt or higher voltage as close to the ECU as possible. The negative side of the cap should got to the ECU ground wire.

Do you happen to remember if the misfire was on a specific cylinder? I'm wondering why my cylinder 4 and 5 have fouled in the first place...

[Kherns]

Very interesting read, as my Stage 2 always had a strange iddle like ta ta da ta ta da during for or five cycles then tadatadatdatdatdatdta and this goes on and repeat itself...:rofl:

[Bitsyncmaster]

Do you happen to remember if the misfire was on a specific cylinder? I'm wondering why my cylinder 4 and 5 have fouled in the first place...

Don't know which cylinders were causing the miss fire. It happened when I replaced the ECU with the chevy ignition module and when the cooling fans were running. I could see the miss fire with the timing light it would fire way advanced just looking at #1 cylinder. I did see large voltage drops with my oscilloscope looking at the voltage at the ECU.

[content22207_2]

If I'm understanding it correctly, GM module does more with its signals than the Bosch module (turning off the coil when ignition's on but the engine isn't spinning for example). I don't think a Bosch module will be as sensitive to run of the mill DeLorean electrical system fluctuations (I've never heard of OEM owners having to add capacitors to solve a misfire -- usually the reason is mechanical, such as a bad injector).

Bill Robertson
#5939

[Bitsyncmaster]

If I'm understanding it correctly, GM module does more with its signals than the Bosch module (turning off the coil when ignition's on but the engine isn't spinning for example). I don't think a Bosch module will be as sensitive to run of the mill DeLorean electrical system fluctuations (I've never heard of OEM owners having to add capacitors to solve a misfire -- usually the reason is mechanical, such as a bad injector).

Bill Robertson
#5939

Correct. The Bosch ECU already has capacitors built into the ECU for power filtering. One brand of the GM module I tested also did not have the "miss" problem so maybe it also has capacitors built into it. It was the AutoZone GM module that had the problem.

In any case, adding more capacitance will only improve the power feed to your ECU. What causes a problem in one car may not show up in other cars. It all depends on how the harness wires run and how good your connections are.

[spikeygg]

I've been searching the forum for more detail on the ignition system and I came across one of Bill's posts from February (http://dmctalk.org/showthread.php?13293-Replacement-Coil-and-Spark-Plug-Wire-Questions&p=191867&viewfull=1#post191867). He said that the polarity is important on the coil so I took a closer look at the one installed in my car and I found that it did not match his description of correct installation.

44245

I looked through the workshop manual and technical information manual and I cannot find anywhere the polarity is published for this. So far Bill hasn't steered me wrong... I don't know if this can cause fouled plugs but I swapped it around and fired her up and she still seems to be missing. I then pulled the idle speed motor in preparation to pull that cylinder 4 plug and the metal pipe was looser than the hoseclamp side and just slide out of the motor.

44246

Do I need to take the intake apart in order to reinstall the metal pipe? I want to relocate this thing like Bill suggested. I think I can just get some properly sized hoses and mount it elsewhere. Then while I was poking around I noticed this hose is just hanging out of the Control Pressure Regulator, it doesn't go anywhere and it has a hoseclamp on it at the Control Pressure Regulator so I'm wondering if it's supposed to be just hanging or should it be hooked up to something?

44247

[spikeygg]

Also, I just noticed from this post (http://www.dmctoday.com/showthread.php?284-How-to-Upgrade-to-High-Energy-Ignition-(HEI)) I think my yellow wire (that goes to the 2.2uF cap) is incorrectly wired. It is currently hooked up to the negative terminal of the coil (with White/Slate), and looking at all the wiring docs it appears that it should be on the positive side (with White/Yellow). Would someone please confirm this for me?

[Bitsyncmaster]

Also, I just noticed from this post (http://www.dmctoday.com/showthread.php?284-How-to-Upgrade-to-High-Energy-Ignition-(HEI)) I think my yellow wire (that goes to the 2.2uF cap) is incorrectly wired. It is currently hooked up to the negative terminal of the coil (with White/Slate), and looking at all the wiring docs it appears that it should be on the positive side (with White/Yellow). Would someone please confirm this for me?

The yellow wire going to the 2.2 uf cap should be wired to the negative terminal of the coil. The case of that cap gets connected to ground which should be the metal plate of the "coil box".

[DMC-81]

Also, I just noticed from this post (http://www.dmctoday.com/showthread.php?284-How-to-Upgrade-to-High-Energy-Ignition-(HEI)) I think my yellow wire (that goes to the 2.2uF cap) is incorrectly wired. It is currently hooked up to the negative terminal of the coil (with White/Slate), and looking at all the wiring docs it appears that it should be on the positive side (with White/Yellow). Would someone please confirm this for me?

Here's a picture of my coil wiring. I don't think it's been touched, but I can't be sure about that. I have an early car and it runs very good.

44249

Based on this discussion, I'd like to find out if it's wired correctly as well.

[content22207_2]

The yellow wire going to the 2.2 uf cap should be wired to the negative terminal of the coil.

Page M:18:03 of the Workshop Manual disagrees, as does the overall wiring diagram at the end of the section -- both show the capacitor on White/Yellow (positive).

That capacitor is only to prevent clicking noises on AM radio, so it's not really critical in today's world.

Bill Robertson
#5939

[content22207_2]

I've been searching the forum for more detail on the ignition system and I came across one of Bill's posts from February (http://dmctalk.org/showthread.php?13293-Replacement-Coil-and-Spark-Plug-Wire-Questions&p=191867&viewfull=1#post191867). He said that the polarity is important on the coil so I took a closer look at the one installed in my car and I found that it did not match his description of correct installation.

44245

I looked through the workshop manual and technical information manual and I cannot find anywhere the polarity is published for this. So far Bill hasn't steered me wrong...

White/Yellow is positive (from the resistor grid). White/Gray or White/Slate is negative (to the ignition ECU).

Bosch coils can be a little confusing. Terminal 15 is positive. Terminal 1 is negative. On Page M:18:03 of the Workshop Manual, Terminal 1 and "WS" is negative.

Every aftermarket coil I have see is labeled + and -.

Ignition coils do not work well wired backwards. The more windings they have, the less well they work backwards (an MSD or Pertronix coil wired backwards will perform worse than a Bosch coil wired backwards).

Bill Robertson
#5939

[spikeygg]

White/Yellow is positive (from the resistor grid). White/Gray or White/Slate is negative (to the ignition ECU).

Bosch coils can be a little confusing. Terminal 15 is positive. Terminal 1 is negative. On Page M:18:03 of the Workshop Manual, Terminal 1 and "WS" is negative.

Hi Bill, I saw that page but there's nothing on there to denote positive and negative terminals, nor terminal 15 vs. 1. There is a '1' next to the coil to label it as such but that's not for the terminals. Here's a screen shot from M:18:03:

44250

You and I are apparently using the same coil and the polarity is clearly stamped on the top. I'm just looking to verify which side within the car should be positive and negative with the manuals but they never seem to indicate...

[spikeygg]

Here's a picture of my coil wiring. I don't think it's been touched, but I can't be sure about that. I have an early car and it runs very good.

44249

Based on this discussion, I'd like to find out if it's wired correctly as well.

Thank you Dana, I can't tell looking at your picture which wires are which. I can see that 15 (+) is toward the bulkhead connectors and 1 (-) is toward the engine side but the white/yellow and white/grey both look just white. Can you verify which is which?

Thanks,
-Greg

[David T]

Thank you Dana, I can't tell looking at your picture which wires are which. I can see that 15 (+) is toward the bulkhead connectors and 1 (-) is toward the engine side but the white/yellow and white/grey both look just white. Can you verify which is which?

Thanks,
-Greg

Coils wired incorrectly will not work as well, Bill is correct. BUT, it would affect all of the plugs equally. If only 1 or 2 plugs are fouling the coil is not the problem. I would replace the spark plugs and see what happens. Be sure to gap them and torque them. A more likely cause of the pug fouling is dirty fuel injectors. For negative ground car systems, which is what you have, the power wire (the WY wire) and the cap should be on the + marked terminal. There is a test that can be done if the terminals have no markings to determine if the polarity is correct.

[content22207_2]

A more likely cause of the pug fouling is dirty fuel injectors.


If all your plugs are firing, pull the injectors to ensure they are all spraying equally and adequately. A weakness of multiport injection is one cylinder's injector can be spraying differently than all the others, causing behavior issues in that cylinder alone.

A bad, or just plain improperly seated, spark plug wire will also cause a misfire.

Bill Robertson
#5939

[Chris4099]

I looked through the workshop manual and technical information manual and I cannot find anywhere the polarity is published for this. So far Bill hasn't steered me wrong... I don't know if this can cause fouled plugs but I swapped it around and fired her up and she still seems to be missing. I then pulled the idle speed motor in preparation to pull that cylinder 4 plug and the metal pipe was looser than the hoseclamp side and just slide out of the motor.

44246

Do I need to take the intake apart in order to reinstall the metal pipe? I want to relocate this thing like Bill suggested. I think I can just get some properly sized hoses and mount it elsewhere. Then while I was poking around I noticed this hose is just hanging out of the Control Pressure Regulator, it doesn't go anywhere and it has a hoseclamp on it at the Control Pressure Regulator so I'm wondering if it's supposed to be just hanging or should it be hooked up to something?

44247

Nobody replied to you on this, so I'll cover it. First, the metal pipe goes into the side of the air meter assembly. There's a hole in the side with an o-ring. So the pipe just slides in and you are good. However, this pipe has been nicknamed the "pipe of agony" over trying to insert it into that hole. However, a simple trick is to let the fuel pressure fully drop and then push the air meter plate all the way down. Now shine a bright light on the side of the manifold while looking inside the air meter assembly and you can see the light come through that hole I mentioned earlier. Use this to help guide you pushing the pipe through. A light coat of grease on the pipe can help slide it in and keep it sealed around the O-ring.

I would advise against relocating the idle controller. There's no quick way to connect to the air meter assembly. Fortunately once you figure out how to connect the tube, removing and reinstalling isn't that bad. Once you get everything working again, you shouldn't have to touch the plugs or the tube for another 30k miles anyway.

As for the open hose on the CPR, that's normal. It's just a vent tube.

[Bitsyncmaster]

Page M:18:03 of the Workshop Manual disagrees, as does the overall wiring diagram at the end of the section -- both show the capacitor on White/Yellow (positive).

That capacitor is only to prevent clicking noises on AM radio, so it's not really critical in today's world.

Bill Robertson
#5939

I think your right. If the cap was on the negative (side driven by the ECU) it would kill the igniton. That's what I get before my 4 cups of coffee in the morning.

[DMC-81]

Thank you Dana, I can't tell looking at your picture which wires are which. I can see that 15 (+) is toward the bulkhead connectors and 1 (-) is toward the engine side but the white/yellow and white/grey both look just white. Can you verify which is which?

Thanks,
-Greg

Hi Greg. Sure. The white/gray wire is on the 1 terminal, and the white/yellow is on the 15 terminal.

Cheers,

[content22207_2]

I would advise against relocating the idle controller. There's no quick way to connect to the air meter assembly.

I couldn't disagree more.

44263

2.7 liter Renault PRV fuel air mixture units have a barb where the so called "pipe of agony" goes. Absolutely no agony whatsoever -- attach a flexible hose to the barb and just leave it there forever after. Whenever you pull the fuel/air mixture unit off, disconnect the hose from the aux air valve or idle speed motor and let it slither out from between the intake runners like a snake through the grass. When it comes time to reinstall the fuel/air mixture unit, thread the hose between the runners then slide the unit the rest of the way in place. Easy peasy.

There is absolutely no good reason to leave the idle speed motor attached to the intake manifold -- not even to pull the engine out of the car.

Bill Robertson
#5939

[Chris4099]

Hmm, you do know he doesn't have a barb already and to install one will take time and money? All to shave a few minutes off accessing a spark plug. If there's an easy way to add a barb (please provide details for us if you know of a way to add one without buying a whole new air meter) while it's out, then by all means. Otherwise, it's too much work for little benefit.

I'll stick to the "pipe of minor discomfort" for now. :)

[content22207_2]

$3.80

http://www.mcmaster.com/#5346k68/=136obab

That pipe seems to cause all sorts to mischief. I've read tales of owners shining a flashlight through the intake runners while they push the air sensor flap open with their other hand trying to see what they're doing to insert it. And the O ring apparently can get knocked loose if you don't hit the hole straight on.

For a couple of dollars I'd much rather do it the French way. That's how I did it for the two years I was K-Jetted.

(Of course this all is a moot point for carb users -- we can pop our entire intake manifold off in 3 minutes and reinstall it just as quickly...).

Bill Robertson
#5939

[Soundkillr]

Bill, stop the carb crap, and keep it on topic. You were asked from the beginning not to start this. Keep your Carb comments to your thread please.

[David T]

Bill, stop the carb crap, and keep it on topic. You were asked from the beginning not to start this. Keep your Carb comments to your thread please.


He can't help himself, he turns every thread into a carb thread. In his defense look how many posts it took till he tried it on this thread!

[content22207_2]

Robert can write 500 word diatribes with impunity, but if I write one sentence the moderator's brain explodes....

Believe it or not, I do know what I am talking about. My car was K-Jetted from 2002 to 2004 with a Renault block (Z7V -- high compression 2.7 liter with Eurospec fueling and ignition). I removed the intake manifold a couple of times in that period, last time to discover that the block had developed a rot hole (ultimately leading to an engine replacement with a fuel delivery system that shall remain nameless...). First time I pulled the K-Jet manifold off I decided there had to be a better place to mount the aux air valve (more or less a rudimentary idle speed motor -- it attaches to the cold start tube and fuel/air mixture unit with 3/4" hoses in the exact same locations). So I simply ran longer hoses and mounted the valve on the driver side pontoon. From that point forward accessing Spark Plug #4 was every bit as easy as accessing Spark Plug #6. And as mentioned fuel/air mixture unit removal and reinstallation was 1,000 times easier.

You all are free to struggle with that pipe if you want. No skin off my nose. But the "Pipe of Agony" is kind of like the "Valley of Death" -- unnecessarily difficult.

Personally I like to make engine maintenance and repair as easy as possible, K-jetted or otherwise.

Bill Robertson
#5939

[Soundkillr]

Robert can write 500 word diatribes with impunity, but if I write one sentence the moderator's brain explodes....

Believe it or not, I do know what I am talking about. My car was K-Jetted from 2002 to 2004 with a Renault block (Z7V -- high compression 2.7 liter with Eurospec fueling and ignition). I removed the intake manifold a couple of times in that period, last time to discover that the block had developed a rot hole (ultimately leading to an engine replacement with a fuel delivery system that shall remain nameless...). First time I pulled the K-Jet manifold off I decided there had to be a better place to mount the aux air valve (more or less a rudimentary idle speed motor -- it attaches to the cold start tube and fuel/air mixture unit with 3/4" hoses in the exact same locations). So I simply ran longer hoses and mounted the valve on the driver side pontoon. From that point forward accessing Spark Plug #4 was every bit as easy as accessing Spark Plug #6. And as mentioned fuel/air mixture unit removal and reinstallation was 1,000 times easier.

You all are free to struggle with that pipe if you want. No skin off my nose. But the "Pipe of Agony" is kind of like the "Valley of Death" -- unnecessarily difficult.

Personally I like to make engine maintenance and repair as easy as possible, K-jetted or otherwise.

Bill Robertson
#5939

Robert writes 500 word diatribes against you, in your own thread. Which I feel you bring on yourself, and try my best to stay out of your thread. I even cleaned it up for you, thank you very much. I may also point out, your carb jabs, do not help the user of this thread. Your other advice may, hence my suggestion to keep carb topics, on your thread. I will also state the obvious, this pipe rarely has to be removed. I installed mine as well (taking 5 minutes out of my life) on my intake 15 years ago, and have not had to go back since. Not once. In 15 years. Yes thats right. My intake has not had to be removed since. Please, everyone, let's get back on topic.

[content22207_2]

I've got a small supply of B28 fuel/air mixture units. Anyone too timid to tap a hose barb in lieu of the "Pipe of Agony", I am more than happy to tap one in on an exchange basis. I won't even charge for my labor -- just pay shipping and a couple of dollars for the barb.

Bill Robertson
#5939

[novadmc]

. I will also state the obvious, this pipe rarely has to be removed. I installed mine as well (taking 5 minutes out of my life) on my intake 15 years ago, and have not had to go back since. Not once. In 15 years. Yes thats right. My intake has not had to be removed since. .

Anecdotal evidence is anecdotal.


Bill, the McMaster link you provided has the barb with a threaded end. Is there currently any barb that can simply be press fit into the orifice? I'd prefer that option for those I'd use who don't want to take a tap and die set to the lower mixture unit housing. I'm considering this mod for the next time I have to monkey with the mixture unit.


As for the Op's post, any update to testing to see what Cyl is acting up?

[Soundkillr]

Novadmc,
I am pointing out that the time it takes to pull a lower intake has little factor once the job has been properly done. All to often it has been brought up how quickly a certain intake can be removed. This has no benifit when there is no need to remove the intake to begin with.
Once the lower intake job is done correctly, you shouldn't have to go back in there for a long time.
I think Bills offer to barb an intake is a generous one....and could offer a great solution for someone struggling with this issue..

[content22207_2]

Geez Louise -- what are you all doing to these things that the O rings fall out? I just removed one and had to pry the retaining ring out with a screwdriver.

Hole in the casting is .765". You'd probably need to use metric tubing to press in, like this: http://www.mcmaster.com/#50295k412/=136ptfp

Fractional tubing tends to jump from 3/4" to 7/8".

You could try using a piece of 3/4" tubing in the stock O ring. Lowes sells 3/4" OD copper tubing in foot long pieces.

Bill Robertson
#5939

[spikeygg]

Wow, this thread went a little sideways for a minute.

Anyway, I used my DMM to check the voltage at "car on" while the engine is not running and I verified that White/Yellow should be the positive side of the coil as it has more potential than the White/Gray side. So I'm confident that I have it hooked up correctly now. However, the yellow wire is baffling me; I think they must have either installed the coil wrong from the factory or incorrectly wrote up the wiring diagram because I don't even have a tabbed terminal on the White/Yellow side with which to hook up the solid Yellow wire! Anyway, if it's for AM radio interference I'm not too worried about it. :)

On the topic of the misfiring cylinders I need some time to try to figure out how to get the idle speed motor relocated or just reinstalled so I can fire it up again. :-/ I plan to do that this weekend when I have more time and more daylight.

[spikeygg]

Nobody replied to you on this, so I'll cover it. First, the metal pipe goes into the side of the air meter assembly. There's a hole in the side with an o-ring. So the pipe just slides in and you are good. However, this pipe has been nicknamed the "pipe of agony" over trying to insert it into that hole. However, a simple trick is to let the fuel pressure fully drop and then push the air meter plate all the way down. Now shine a bright light on the side of the manifold while looking inside the air meter assembly and you can see the light come through that hole I mentioned earlier. Use this to help guide you pushing the pipe through. A light coat of grease on the pipe can help slide it in and keep it sealed around the O-ring.

I would advise against relocating the idle controller. There's no quick way to connect to the air meter assembly. Fortunately once you figure out how to connect the tube, removing and reinstalling isn't that bad. Once you get everything working again, you shouldn't have to touch the plugs or the tube for another 30k miles anyway.

As for the open hose on the CPR, that's normal. It's just a vent tube.

Chris, thanks for this response. Very helpful.

[DMC-81]

Wow, this thread went a little sideways for a minute.

Anyway, I used my DMM to check the voltage at "car on" while the engine is not running and I verified that White/Yellow should be the positive side of the coil as it has more potential than the White/Gray side. So I'm confident that I have it hooked up correctly now. However, the yellow wire is baffling me; I think they must have either installed the coil wrong from the factory or incorrectly wrote up the wiring diagram because I don't even have a tabbed terminal on the White/Yellow side with which to hook up the solid Yellow wire! Anyway, if it's for AM radio interference I'm not too worried about it. :)

On the topic of the misfiring cylinders I need some time to try to figure out how to get the idle speed motor relocated or just reinstalled so I can fire it up again. :-/ I plan to do that this weekend when I have more time and more daylight.

On my car, on the positive side of the coil, there is an interim connector to which you fasten the white/yellow and yellow wire. Then, that connector is fastened to the 15/+ terminal. Or, depending on the coil that you are using, you can get something like this...http://store.delorean.com/p-6866-male-blade.aspx

44266

[spikeygg]

Success!! Tonight I pulled that cylinder 4 plug and it was soaking wet with fuel, I peered down into the spark plug hole with my flashlight and it looked like liquid down there so I make a little dipstick to see if I could grab some.

44273

I got most of the fluid out of the cylinder #4, I cleaned up the plug and tested the #4 spark plug wire, it was firing well. So I put it back together and fired the engine up, SOUNDS GOOD NOW! :)

Here's a quick video I shot of the two pipes now:

https://www.youtube.com/watch?v=88JkqCFc0Iw

I checked the timing after this and I have some questions. I understand that the stock timing should be 13±2°, when I looked at my timing it was reading 0° (timing light hooked to cylinder #1, closest to the coil). I loosened the distributor and moved it a bit forward and the idle raised up, I checked the timing again and it was 4°. So I moved it a little more, the idle raised again and I checked the timing: 8°. I tried pushing it a little more and when I checked the timing the mark was bouncing all over, it did not seem consistent. Any ideas about this?

Is there somewhere I can adjust the idle speed down after adjusting the timing up?

After all that I realized that the plate that the timing marks are made on is adjustable. I wonder what the procedure is to verify that the timing is accurate? Do I need to get cyl#1 to TDC and that will correspond with 0° on the crank?

Thanks for all the help, so far so good!

[content22207_2]

Ensure the timing scale is accurate before adjusting the distributor. If the scale is not accurate, you will end up mistiming the engine, which can lead to all sorts of problems.

The PRV has a nifty way of positioning the engine 100% TDC #1:

44274 44275 44276

This is what an ordinary 5/16" drill bit looks like riding on the counterweight, then dropping into the index hole:

44277 44278

There isn't enough clearance to use a drill bit with the water pump in place, but a 7mm allen wrench fits just fine in that circumstance (water pump in place):

44279 44280

There are all sorts of exotic indexing techniques that typically involve sticking things through the spark plug hole into the cylinder. Biggest problem with those techniques is the piston sits at an angle to the spark plug -- TDC will likely be close, but not 100% accurate. Using the proper PRV index hole is 100%.

Note that 3.0's have no provision for indexing -- only 2.7's and 2.8's.

Bill Robertson
#5939

[spikeygg]

This is what an ordinary 5/16" drill bit looks like riding on the counterweight, then dropping into the index hole:

44277 44278


This is AWESOME, thanks for the photos. This helps immensely. What all do I need to remove in order to get to this? Those first set of photos look like a pretty bare block. :-/

I also need to find or purchase a 35mm socket!! HOLY COW.

By the way, I don't know if anyone has seen this before but I can't get a good read on my timing. Here's a (bad) video of what it looks like. The timing mark jitters all over the map. Any ideas on this?

https://www.youtube.com/watch?v=G-2od9CvMmM

[content22207_2]

If you're indexing an installed engine, use an allen wrench instead. Those pictures were taken on #5939. Adjusting screw on the heater core return line hose clamp was in the way, so I loosened it up and slid it down the hose. Otherwise all I did was pop the intake manifold off, which admittedly is faster and easier on some cars than on others (well less than 5 minutes in #5939's case, so I take the manifold off quite frequently, for example to take those allen wrench pictures).

Bill Robertson
#5939

[Bitsyncmaster]

Is there somewhere I can adjust the idle speed down after adjusting the timing up?

Your curb idle probably needs to be set. That is what holds the throttle plates open a little. The two screws on the throttle arm need to be moved CCW.

[content22207_2]

Over advanced timing will have higher than normal idle. You'll know if the engine is over advanced as soon as you start to drive it -- will be predetonating like crazy (assuming distributor advance mechanisms are working normally).

Bill Robertson
#5939

[spikeygg]

Could someone please take a picture of their crank pulley where the timing mark is supposed to be and what it looks like? I inspected my pulley and it appears to have two timing marks on it.. :(

4428244283

The first picture taken from the bottom shows a notch on the inside of the pulley as well.

[content22207_2]

Two timing marks are 150 degrees apart. Mark to the right of the acute angle is TDC #1, mark to the left of the acute angle is TDC #6. See inset graphic:

44284

Bill Robertson
#5939

[spikeygg]

Two timing marks are 150 degrees apart. Mark to the right of the acute angle is TDC #1, mark to the left of the acute angle is TDC #6. See inset graphic:

44284

Bill Robertson
#5939

What the heck? How does one set timing with two marks? I guess this makes it possible to use cyl#6 or cyl#1? Are they not supposed to interfere with each other when the timing light flashes? Maybe I'll try checking timing with cyl#6 instead of #1.

Also, where can I get this book you're referencing? :)

[content22207_2]

TDC Cylinder 1:

44285

TDC Cylinder 6:

44286

If you clip the timing light on Cylinder 1's wire, use Cylinder 1 mark. If you clip the timing light on Cylinder 6's wire, use Cylinder 6 mark.

Timing scale can only be indexed (using hole in the counterweight) using Cylinder 1 mark.

Scans are from Volvo factory literature. Vastly superior to the Engine section of the DeLorean Workshop Manual. eBay is a good source of Volvo manuals (don't forget to search British eBay too: www.ebay.co.uk). Be advised: Volvo stopped using actual photographs ~1985, but the line drawings were colorized. This is an example of the later colorized line drawings:

44287

Bill Robertson
#5939

[content22207_2]

Figure 28 on Page C:05:03 of the Workshop Manual is a typo. 10 degrees BTDC is Volvo/Renault's timing spec (Volvo and Renault distributors have more aggressive advance curves). By the time Renault finished dumbing down the DeLorean PRV, base ignition time was bumped up to 13 degrees.

Bill Robertson
#5939

[content22207_2]

You do realize Sharpie marks on your crankshaft pulley are in the wrong place?

44292

Use the notches. The crankshaft pulley can only be installed one way (it has a keyway -- assuming the woodruff key in fact is in place).

If your crankshaft pulley is missing its woodruff key all bets are off. In that instance you have no choice but to index the timing scale and make a new TDC mark.

Or pull the pulley off and put a woodruff key back in place.

Bill Robertson
#5939

[spikeygg]

You do realize Sharpie marks on your crankshaft pulley are in the wrong place?

44292

Use the notches. The crankshaft pulley can only be installed one way (it has a keyway -- assuming the woodruff key in fact is in place).

If your crankshaft pulley is missing its woodruff key all bets are off. In that instance you have no choice but to index the timing scale and make a new TDC mark.

Or pull the pulley off and put a woodruff key back in place.

Bill Robertson
#5939

Yeah, I saw that, can you please respond with a photo of your pulley showing the sharpie mark at the same point as the notch in the crankshaft pulley? I'd like to verify what a correct one looks like before I tear it down. I know on my 3000GT the timing notch is NOT in the same spot as the "sharpie" mark used with a timing gun.

[spikeygg]

By the way, I don't know if anyone has seen this before but I can't get a good read on my timing. Here's a (bad) video of what it looks like. The timing mark jitters all over the map. Any ideas on this?

https://www.youtube.com/watch?v=G-2od9CvMmM

I figured out what was going wrong with this. I'm dumb, I took this measurement with the airbox still on the car and I was using cylinder #1, I hooked it up closer to the distributor and I think it was picking up more than just cylinder #1. I tried it again this morning with cylinder #6 (right at the plug, because it's much more accessible) and the timing is VERY stable. I still would like to verify that the scale is correct for the engine.

As a side note, I looked for the little metal timing scale piece on DeLorean Motor Company's webpage because mine has some rust on it, WTF!? $93?!? :mad2: Guess I'll stick with my rusted one...

[content22207_2]

Sharpie mark isn't factory -- somebody else put that on.

From the factory all you have are notches:

44293 44294

My guess is a PO estimated TDC with something stuck through the spark plug hole then drew the mark. That is a very inexact way to find TDC. And it begs the question: why did he do it in the first place? If you index the engine using the hole in the counterweight and discover TDC 1 notch is nowhere near the scale, I would strongly suspect the woodruff key is missing from the crankshaft (and would explain why the PO drew a new mark).

Bill Robertson
#5939

[spikeygg]

Sharpie mark isn't factory -- somebody else put that on.

From the factory all you have are notches:

44293 44294

My guess is a PO estimated TDC with something stuck through the spark plug hole then drew the mark. That is a very inexact way to find TDC. And it begs the question: why did he do it in the first place? If you index the engine using the hole in the counterweight and discover TDC 1 notch is nowhere near the scale, I would strongly suspect the woodruff key is missing from the crankshaft (and would explain why the PO drew a new mark).

Bill Robertson
#5939

Wow, yeah, I hadn't realized that. Crap. In fact my little metal scale thing looks different than yours too. Dammit. I really need to tear it apart and verify TDC and the notch/sharpie marks/woodruff key.

How difficult is it to take the intake off? Do I need to pull the distributor too? I'm guessing the fuel distributor has to come out. Is there a published procedure for removing all this stuff somewhere? I've been looking for the B27/B28 Engine Reconditioning Manual pdf but I have not been able to find it. I don't want to buy a book from eBay, I prefer to have the electronic version. I found this site: http://www.volvotips.com/index.php/240-260/volvo-240-260-service-manual/ they have PDFs to a lot of these manuals but not the one I'm looking for. :cry:

EDIT: I found the manual (here: http://goo.gl/BFSy8)

[content22207_2]

Take the crankshaft pulley nut off. That will allow you to see the keyway to verify the woodruff key is in place.

Bill Robertson
#5939

[David T]

Take the crankshaft pulley nut off. That will allow you to see the keyway to verify the woodruff key is in place.

Bill Robertson
#5939

Just pull #1 spark plug and crank the cylinder up to Top Dead Center (TDC) after the intake valve closes. That would be the compression stroke. Now look at the timing marks. If it isn't indicating TDC either the pulley is off or the indicator needs to be adjusted. Make sure you are actually checking the correct cylinder. Refer to C:01:01. Cylinder #1 is towards the front on the right side when standing at the rear of the car looking forward.

[content22207_2]

Just pull #1 spark plug and crank the cylinder up to Top Dead Center (TDC) after the intake valve closes.

That's the trick -- how do you know when the piston's at TDC? Sticking things through the spark plug hole gets you close, but it's very difficult to be 100% because the piston sits at an angle to the spark plug. Certainly not precise enough to reset the timing scale. That's why the nice people in Douvrin drilled an indexing hole in #6 counterweight -- the indexing hole is 100% TDC.

Bill Robertson
#5939

[David T]

As a rough check it is a quick and easy way to do it. You can stick a paper straw into the cylinder and watch it come up to TDC and be reasonably close. Close enough to see if the index marks are where they should be.

[sdg3205]

That's the trick -- how do you know when the piston's at TDC? Sticking things through the spark plug hole gets you close, but it's very difficult to be 100% because the piston sits at an angle to the spark plug. Certainly not precise enough to reset the timing scale. That's why the nice people in Douvrin drilled an indexing hole in #6 counterweight -- the indexing hole is 100% TDC.

Bill Robertson
#5939

Yeah, but wouldn't he have to remove the water pump?

[content22207_2]

I was able to use an allen wrench in lieu of a drill bit with the water pump in place:

44322 44323

(Don't ask me where I got the idea it was 7mm -- appears to have been 1/4").

A 5 inch long drill bit is too long to clear the heater core return line (indexing hole is a very tight tolerance fit, and the heater core return line cocks the drill bit just enough that it won't slide through). You could cut a drill bit down to 3", or perhaps just bend it slightly 3" up the shaft. I used an allen wrench partly because it was handy, and partly because I wanted the L shaped handle in case it fell too far into the engine, which really isn't anything to worry about because the drop is only 1/4" or so.

I've got plenty of drill bits -- after church I will pop my intake manifold off and take some pics with a cut down or bent drill bit.

Bill Robertson
#5939

[content22207_2]

Nevermind -- I decided to do it this morning (you all love to give me crap about my carburetor, but it does allow you to pop the intake manifold off at 7:00 in the morning).

Using a 3 inch long 5/16" bolt:

44324

Bolt before and after dropping into the index hole:

44325 44326

I keep telling you all, there is a quicker and easier way to do this....

Bill Robertson
#5939

[spikeygg]

Nevermind -- I decided to do it this morning (you all love to give me crap about my carburetor, but it does allow you to pop the intake manifold off at 7:00 in the morning).

Using a 3 inch long 5/16" bolt:

44324

Bolt before and after dropping into the index hole:

44325 44326

I keep telling you all, there is a quicker and easier way to do this....

Bill Robertson
#5939

Thanks for doing this Bill, I get that it's easier with your carb but I do not have that luxury at this point. Do you know if I can just unbolt the mixture control unit/intake manifold from the engine and pull it out of the way to get to this? I'd rather not have to disconnect all these fuel lines but it seems pretty deep in the engine bay. Looking at the 1980 Volvo B28F manual, they describe it like this:

Detach intake manifold with air-fuel control unit
Move hoses and cables to one side, disconnect as necessary. Clean fuel line connections thoroughly before disconnecting pipes. Detach wiring and place harness on top of radiator panel. Remove intake manifold with air-fuel control unit.

This almost makes it sound like you can remove the mixture control unit and intake manifold while they are still attached to one another but I'm guessing this is not the case.

[content22207_2]

I believe that is how most K-Jetters remove their intake manifold. They leave the injector lines attached to the fuel distributor and pop the injectors out of the heads. Don't forget to remove the throttle spool.

Some K-Jetters report being able to remove their intake manifold in 15-20 minutes. Definitely should be a goal (there's a lot of stuff under the intake manifold).

Bill Robertson
#5939

[content22207_2]

Coincidentally I was looking at the first K-Jet iteration earlier this morning (1975-1978 ). Volvo recommends removing it as one unit, with the fuel lines still attached:

44336

Bill Robertson
#5939

[spikeygg]

I believe that is how most K-Jetters remove their intake manifold. They leave the injector lines attached to the fuel distributor and pop the injectors out of the heads. Don't forget to remove the throttle spool.

Some K-Jetters report being able to remove their intake manifold in 15-20 minutes. Definitely should be a goal (there's a lot of stuff under the intake manifold).

Coincidentally I was looking at the first K-Jet iteration earlier this morning (1975-1978 ). Volvo recommends removing it as one unit, with the fuel lines still attached:

44336


Is there any special trick to popping the injectors out of the head? I just pull up on the body of the injector?

[David T]

Is there any special trick to popping the injectors out of the head? I just pull up on the body of the injector?

You must pop off the spring first. Easy to do with a screwdriver. Most will remove all of the hoses from one side (usually the left side) and lay the mixture unit over on the right side. As for Bill. this is not a contest as to how quickly you can do any particular job. It is not like you do this often once you get the motor running well. Getting back to the timing, which is what you are trying to do, since you have custom cams you should figure out what base timing you want, 13 BTDC is probably not the best for you anymore. One way to set the timing is what used to be called "Power Tuning". Get the highest octane gas you can find and keep advancing the timing till you get detonation and then back off 2 degrees. You may find you are right back to where you started. Get the car hot and go up a hill and see if you get detonation (pinging).

[content22207_2]

He needs to verify TDC #1 before doing anything else. Until he knows with certainty where TDC is, moving the distributor around is just guessing (or blind faith).

Somebody put that mark -- notably distant from the factory TDC notch -- on his crankshaft pulley for a reason.

Bill Robertson
#5939

[Soundkillr]

Nevermind -- I decided to do it this morning (you all love to give me crap about my carburetor, but it does allow you to pop the intake manifold off at 7:00 in the morning).

Using a 3 inch long 5/16" bolt:

44324

Bolt before and after dropping into the index hole:

44325 44326

I keep telling you all, there is a quicker and easier way to do this....

Bill Robertson
#5939

Bill do I really have to say it again? You will be asked to leave if you turn every single thread into a rolling commercial for a carburetor. This type of behavior pissed off alot of the community and increases aggression toward you, making things more difficult. PLEASE stop.

[content22207_2]

On June 26 spikeygg reported this car as a newly acquired. It isn't as though he's been driving it for a while and new problems have cropped up.

There's no telling what a PO may have done before spikeygg got the car. He needs to establish some base lines of his own.

Verifying TDC #1 is a good start. Even sticking things through the spark plug hole is better than flying blind.

Bill Robertson
#5939

[sdg3205]

Actually Bill, no one gives you any crap for having a carb, but I get the feeling you'd like us to. You're starting the "poor me" stuff again. Let's not instigate shall we?

If you want to sell the OP on a carb conversion use PM. This space is for problem solving, not 'how much better it is to problem solve with a carb.'

[spikeygg]

So I've been hunting down the Volvo parts manual to see if I can get a better price for the "official" DeLorean timing plate (scale ignition setting). I figure my timing plate is from some other engine:

44338

You can see that it completely covers both edges of the crank pulley and definitely covers the timing notches. As I'm looking for the part number of the timing plate that looks like Bill's, I find the Volvo parts catalog on this page (http://www.volvotips.com/index.php/240-260/volvo-240-260-brochures/). And navigating through the many pages I found this:

44339
from page 127/1371

Now I'm thinking what the hell? That's the same one that's on my car. So maybe it is original... but how the heck am I supposed to set the timing on this thing when I can't see the notches?? As I'm looking for the smaller plate in that same manual about 15 pages later I see this:

44340
from page 143/1371

So clearly, they had the smaller plate and this bigger one but, for the life of me, I cannot find the smaller plate's part number in this catalog.

Does anyone know what is going on here?? It seems, after all, that I have an OEM timing plate after this research, even though it's completely different than the other examples posted here, but I don't know how I'm supposed to set timing using the crank pulley notches with this setup.

[content22207_2]

Does your plate have degree markings? If it does, go ahead and use it.

You can make a timing mark somewhere else on the pulley, visible against your plate. That's not a problem. The problem is the mark someone else made doesn't match factory TDC. That is suspicious. If your pulley is in fact a PRV pulley, TDC can not change from the factory notch unless the pulley is not keyed to the crankshaft anymore (pulley is shifting on its own).

Even if it is just a straw stuck through the spark plug hole, you need to get an idea where TDC is. You could discover that neither the notch nor the Sharpie mark are correct.

Bill Robertson
#5939

[content22207_2]

You're starting the "poor me" stuff again.

Not poor me -- I can pop my manifold off first thing in the morning, index the engine, document my labors, and have the car buttoned back up a ready for church before breakfast. I am sure there are plenty of poor DeLorean owners out there, but I am not one of them.

And before you climb too high on your pedestal, remember that you were the one posting incorrect information (that the engine can not be indexed with the water pump in place). That is 100% incorrect. The only reason I popped my intake manifold off was to take some correct pictures.

Bill Robertson
#5939

[sdg3205]

It's great to have you back bill.

[spikeygg]

You must pop off the spring first. Easy to do with a screwdriver. Most will remove all of the hoses from one side (usually the left side) and lay the mixture unit over on the right side.


Does your plate have degree markings? If it does, go ahead and use it.

You can make a timing mark somewhere else on the pulley, visible against your plate. That's not a problem. The problem is the mark someone else made doesn't match factory TDC. That is suspicious. If your pulley is in fact a PRV pulley, TDC can not change from the factory notch unless the pulley is not keyed to the crankshaft anymore (pulley is shifting on its own).

I know all of this Bill. I'm mostly curious and interested in how someone is expected to set the timing by using the stock equipment (notches on the pulley and this particular timing plate) without making marks on the pulley, the vehicle should be thus designed, no? I am not doubting that the marks are in the wrong spot. I also don't doubt that the graduated timing plate has been shifted left or right so I am approaching this as if non of it is accurate. I reset my timing back to full counter clockwise (retarded) so I don't blow up the engine for the time being.

What I need help with is trying to get into that area. I plan on doing this late next week, I need to drive the car to the DMV first to get it registered early in the week; and, just now, I discovered that there is a coolant leak coming from somewhere within the area under the intake manifold so I definitely need to disassemble the mixture unit and intake so I can fix that as well. Do you guys have ideas where the coolant leak may be coming from? I heard that the water pump is under there, and it looks like there's a big hose running in there but I can't see much except a lot of green anti-freeze. :(

Dave, thanks for the info here. Is the "spring" the little black circle thing with the four tabs extending down on each of the injectors? Do I just slip the screw driver between the injector and the circle and pry the spring up? You also mentioned that it might be easier to just pull one side, do you mean pull all injectors from one side and unbolt the intake laying everything down on the other side of the engine bay? If the injectors are easy-ish to pull up I might just try to pull the whole thing. I wish there was a step-by-step procedure somewhere. I'm not really liking this description from the Volvo manual.

[Rich]

.....What I need help with is trying to get into that area. I plan on doing this late next week, I need to drive the car to the DMV first to get it registered early in the week; and, just now, I discovered that there is a coolant leak coming from somewhere within the area under the intake manifold so I definitely need to disassemble the mixture unit and intake so I can fix that as well. Do you guys have ideas where the coolant leak may be coming from? I heard that the water pump is under there, and it looks like there's a big hose running in there but I can't see much except a lot of green anti-freeze.

This is where you are headed on the coolant plumbing under the intake manifold. http://store.delorean.com/c-270-1-3-0-water-pump.aspx

Go to this post [HERE (http://dmctalk.org/showthread.php?429-How-to-Removing-intake-manifold)] and download the pdf to see what's involved in pulling the intake manifold. Be aware that you need some gaskets and o-rings to put it back together even if nothing's wrong.

The area underneath it is called the Valley of Death or the VOD. It's where the back of the water pump connects to the cast Y-pipe that in turn connects to the coolant galleys in both cylinder heads. There are also sensors screwed into the Y-pipe. Coolant can leak from a few spots. Almost impossible to predict what is leaking before you go in - unless you have a borescope.

Get a coolant pressure tester - with that you can easily find whatever is leaking after you get the manifold off.

At the end of the how-to you will see a list of while-in-there jobs you'll want to consider doing in addition to any leak repair. Be sure you pressure-test the cooling system before you put the intake manifold back on. Have fun in there.

[spikeygg]

This is where you are headed on the coolant plumbing under the intake manifold. http://store.delorean.com/c-270-1-3-0-water-pump.aspx

Go to this post [HERE (http://dmctalk.org/showthread.php?429-How-to-Removing-intake-manifold)] and download the pdf to see what's involved in pulling the intake manifold. Be aware that you need some gaskets and o-rings to put it back together even if nothing's wrong.

The area underneath it is called the Valley of Death or the VOD. It's where the back of the water pump connects to the cast Y-pipe that in turn connects to the coolant galleys in both cylinder heads. There are also sensors screwed into the Y-pipe. Coolant can leak from a few spots. Almost impossible to predict what is leaking before you go in - unless you have a borescope.

Get a coolant pressure tester - with that you can easily find whatever is leaking after you get the manifold off.

At the end of the how-to you will see a list of while-in-there jobs you'll want to consider doing in addition to any leak repair. Be sure you pressure-test the cooling system before you put the intake manifold back on. Have fun in there.

My savior! This is exactly what I needed, you're a gentleman and a scholar! As it turns out I have a borescope so I can probably try to figure it out but it won't change what I have to do. Great idea about the coolant pressure tester, I didn't even know they existed. I found one on Harbor Freight but it's $90, I wonder if I can build a pressure tester out of plumbing supplies and hook up my air compressor. I just need to give it a little pressure so coolant starts spraying from the leak point.

Thank you so much for the link to the PDF.

[Rich]

Glad to hear that pdf how-to gets you what you need.

The borescope will still be a pain since you need to thread it in from the back of the manifold but you sound like you're up for challenges. No guarantee a borescope shows all sides of all (four) hoses or all connections on Y-pipe. Also possible there is a pool of coolant hiding things you need to see...but it's a start.

Recommending you spend the money to get a good pressure tester sooner than later - you need it after any cooling system work to be sure it holds 15PSI for a good length of time, something an air compressor just won't do - and an air compressor won't regulate well at 15PSI. Looking for leaks is one thing, making sure there are no leaks anywhere in a system is another.

This is a reference shot of what you'll be seeing on top of the engine minus the intake manifold. Back of the pump is at left, distributor at upper right, Y-pipe in the middle. Photo cred to Clint on this one: LINK: reference shot of PRV VOD (http://s31.photobucket.com/user/vwdmc16/media/dmc/CIMG2292-1.jpg.html)

[novadmc]

My savior! This is exactly what I needed, you're a gentleman and a scholar! As it turns out I have a borescope so I can probably try to figure it out but it won't change what I have to do. Great idea about the coolant pressure tester, I didn't even know they existed. I found one on Harbor Freight but it's $90, I wonder if I can build a pressure tester out of plumbing supplies and hook up my air compressor. I just need to give it a little pressure so coolant starts spraying from the leak point.

Thank you so much for the link to the PDF.

pick up this MityVac to do your pressure testing:
https://www.amazon.com/Mityvac-MV4560-Radiator-Cooling-Pressure/dp/B003V9L05G/ref=sr_1_13?ie=UTF8&qid=1468185877&sr=8-13&keywords=mityvac

one of the supplied caps goes right on where the radiator cap goes on the overflow tank. then you jut pump away till 14-15psi and see what leaks.

I had the same issue a few weeks ago which required taking the manifold off (i was replacing fuel lines anyways and that's like 1/2 the disassembly process anyways). luckily for me, it was just the hose clamp that needed a good tightening down on the hose that connects the pump to the y-pipe.

hose clamp in question was the the upper clamp, connecting to the y-pipe in the below pic.
44355

[spikeygg]

pick up this MityVac to do your pressure testing:
https://www.amazon.com/Mityvac-MV4560-Radiator-Cooling-Pressure/dp/B003V9L05G/ref=sr_1_13?ie=UTF8&qid=1468185877&sr=8-13&keywords=mityvac

one of the supplied caps goes right on where the radiator cap goes on the overflow tank. then you jut pump away till 14-15psi and see what leaks.

I had the same issue a few weeks ago which required taking the manifold off (i was replacing fuel lines anyways and that's like 1/2 the disassembly process anyways). luckily for me, it was just the hose clamp that needed a good tightening down on the hose that connects the pump to the y-pipe.

hose clamp in question was the the upper clamp, connecting to the y-pipe in the below pic.
44355

Awesome, I bought this MityVac tester and a 35mm socket from Amazon. With that pressure tester I'll be able to really make sure there aren't any leaks before buttoning it all up, right? Much better than throwing it all back together and then finding out there's a leak in the VOD. :P

[David T]

Awesome, I bought this MityVac tester and a 35mm socket from Amazon. With that pressure tester I'll be able to really make sure there aren't any leaks before buttoning it all up, right? Much better than throwing it all back together and then finding out there's a leak in the VOD. :P

All of that work just to verify the timing marks? You are in for a LOAD of work and if you go ahead with a Master Water Pump Kit as most of the vendors call it, a LOT of money. The spring clips just pop off using your fingers or a screwdriver. You can "lay" most of it over out of the way but not all, you still will have to disconnect some hoses. If all you are after is verifying the timing marks, try my method first. Otherwise one of your next posts will be asking how to drill out broken off bolts!

[spikeygg]

All of that work just to verify the timing marks? You are in for a LOAD of work and if you go ahead with a Master Water Pump Kit as most of the vendors call it, a LOT of money.

Apparently you didn't read the part where I said: "I have a coolant leak". I might try it your way if I didn't have a coolant leak but now I've got some repairs to do as well. This engine is basically new so I'm not worried about breaking bolts and replacing water pumps, but thanks for the reply anyway.

[novadmc]

Apparently you didn't read the part where I said: "I have a coolant leak". I might try it your way if I didn't have a coolant leak but now I've got some repairs to do as well. This engine is basically new so I'm not worried about breaking bolts and replacing water pumps, but thanks for the reply anyway.

use pb blaster on bolts before attempting to break them free if unsure of their condition and then use anti-seize on each one as you reinstall. take your time and the bolts should play nice with you. I got lucky and didn't break any bolt coming out of the engine.

take pics as you go to aid in re-installation so you can quickly identify where each plug, bolt, etc goes.

[David T]

Apparently you didn't read the part where I said: "I have a coolant leak". I might try it your way if I didn't have a coolant leak but now I've got some repairs to do as well. This engine is basically new so I'm not worried about breaking bolts and replacing water pumps, but thanks for the reply anyway.

Pressure test the system before taking the intake manifold off. This started as a miss at idle and is now becoming a "top job". For a "new" engine this is turning into a big deal. If the leak is small try a can of Barr's Stop Leak.

[novadmc]

If the leak is small try a can of Barr's Stop Leak.

that stuff's a temp fix IMO. anything you're adding to "fix" something (stop leak, an egg, etc) is just buying time. just cause the engine's "new" doesn't mean something wasn't properly torqued down down in the valley. might as well diagnose it and do it right (but I do agree, pressure test before removing anything and stick a borescope/inspection camera down into the valley from behind the fuel distributor to see what's going on 1st). and then get to fixing it right.

[spikeygg]

that stuff's a temp fix IMO. anything you're adding to "fix" something (stop leak, an egg, etc) is just buying time. just cause the engine's "new" doesn't mean something wasn't properly torqued down down in the valley. might as well diagnose it and do it right (but I do agree, pressure test before removing anything and stick a borescope/inspection camera down into the valley from behind the fuel distributor to see what's going on 1st). and then get to fixing it right.

Agreed on the temp fix opinion. I want to do this correctly so I don't have to worry about it. By the way, I'm in the garage now and I tried the pressure tester/borescope without disassembling anything and I can see the leak...

https://youtu.be/d24kxPTN-3w


https://youtu.be/d24kxPTN-3w

[spikeygg]

Nevermind -- I decided to do it this morning (you all love to give me crap about my carburetor, but it does allow you to pop the intake manifold off at 7:00 in the morning).

Using a 3 inch long 5/16" bolt:

44324

Bolt before and after dropping into the index hole:

44325 44326

I keep telling you all, there is a quicker and easier way to do this....

Bill Robertson
#5939

Hi Bill,

Regarding your message I got to the plug. Now I am wondering what I do, just put the 5/16 inch Bolt into the hole and start turning the crank, watching for the Bolt to drop? When it drops is that cylinder 1 top dead center?

I tried to watch the video from your how to thread but the animated gif didn't work.

44598

Thanks,
-Greg

[novadmc]

Agreed on the temp fix opinion. I want to do this correctly so I don't have to worry about it. By the way, I'm in the garage now and I tried the pressure tester/borescope without disassembling anything and I can see the leak...

https://youtu.be/d24kxPTN-3w


https://youtu.be/d24kxPTN-3w

hose clamp on the larger (Y) pipe hose? same one i had loosen and cause a leak. crank that effer down as tight as you can (and tighten all the others for good measure while you're there.

[spikeygg]

hose clamp on the larger (Y) pipe hose? same one i had loosen and cause a leak. crank that effer down as tight as you can (and tighten all the others for good measure while you're there.

To be honest, these hoses look (like expensive) aftermarket and they have some deep hoseclamp impressions which makes me think that they were clamped down pretty good and at this point I think they could be considered "old". I'm just going to order some OEM ones from www.delorean.com and replace them since they're less than $10 for the pair. I need to order the copper crush washers anyway since I wasn't able to find all of them in town...

I used the hole to verify TDC, I'm guessing this hole is for cylinder #1 and the other hole is for cylinder #2.


https://youtu.be/yfQWUvmthFo
https://youtu.be/yfQWUvmthFo
When the bolt drops, we're on TDC for #1, right?

After I did this operation the crank pulley looks like this:
44599

It looks like cylinder#1 crank mark is pretty close, if anything maybe retarded by a degree or two. However, I'm thinking maybe I should do this to the cylinder #6 mark too since it seems to be a lot easier to set the timing using the cylinder #6 plug wire. It just looks like I have to pull the water pump in order to check cylinder #6, so maybe I won't. Thoughts?

[content22207_2]

Other plug goes into the oil galley -- leave it alone. If you do remove it you may need a new crush washer. Oil is under even higher pressure than K-Jet fuel. An owner who removed his galley plug reported problems resealing it (a new oil pan washer ultimately stopped the leaks).

Engine indexing hole isn't under any pressure (slight PCV vacuum actually).

Bill Robertson
#5939

[content22207_2]

After I did this operation the crank pulley looks like this:
44599

It looks like cylinder#1 crank mark is pretty close, if anything maybe retarded by a degree or two.

I still am puzzled why your factory timing notch is so far off. In theory it shouldn't move even a fraction of an inch due to the woodruff key.

May as well reset your timing scale using the Sharpie mark, then check it from time to time to ensure the Sharpie mark remains at 13 degrees. If the Sharpie mark ever moves, your woodruff key almost certainly is missing (assuming the distributor is tightened down all the way).

Bill Robertson
#5939

[spikeygg]

I still am puzzled why your factory timing notch is so far off. In theory it shouldn't move even a fraction of an inch due to the woodruff key.

May as well reset your timing scale using the Sharpie mark, then check it from time to time to ensure the Sharpie mark remains at 13 degrees. If the Sharpie mark ever moves, your woodruff key almost certainly is missing (assuming the distributor is tightened down all the way).

Bill Robertson
#5939

I'm pretty sure it's because I have the "alternate" style timing plate, it doesn't look anything like yours. This style plate is stock but doesn't allow me to use the standard crank pulley notches like you can. I'm still left wondering HOW any mechanics set the timing with this timing plate without manually marking up the pulley...

[content22207_2]

Surely you have a stock crankshaft. Pulley is keyed to the crankshaft, so theoretically it can't move from TDC. Your #1 notch however is nowhere near verified TDC. The scale can move, but not *THAT* much (assuming your scale is a PRV scale of some ilk, not a scale from a totally different engine, or a generic aftermarket scale).

Your notch looks to be at least 20 degrees off, if not more -- really odd:

44610

Bill Robertson
#5939

[content22207_2]

Since you know where TDC is, reset your timing scale to the Sharpie mark and run with it.

Periodically recheck the timing (with a timing light). If the Sharpie mark moves from 13 degrees BTDC, your pulley likely is moving around.

Bill Robertson
#5939

[content22207_2]

(assuming your scale is a PRV scale of some ilk, not a scale from a totally different engine, or a generic aftermarket scale)

Any timing scale will work (13 degrees is 13 degrees). But if your scale is made for a different application it may well bolt up differently on the timing chain cover, which would explain why TDC on the scale isn't anywhere near the notch.

Bill Robertson
#5939

[spikeygg]

Surely you have a stock crankshaft. Pulley is keyed to the crankshaft, so theoretically it can't move from TDC. Your #1 notch however is nowhere near verified TDC. The scale can move, but not *THAT* much (assuming your scale is a PRV scale of some ilk, not a scale from a totally different engine, or a generic aftermarket scale).

Your notch looks to be at least 20 degrees off, if not more -- really odd:

44610

Since you know where TDC is, reset your timing scale to the Sharpie mark and run with it.

Periodically recheck the timing (with a timing light). If the Sharpie mark moves from 13 degrees BTDC, your pulley likely is moving around.

Any timing scale will work (13 degrees is 13 degrees). But if your scale is made for a different application it may well bolt up differently on the timing chain cover, which would explain why TDC on the scale isn't anywhere near the notch.

Bill Robertson
#5939

I think the piece your overlooking is that this alternate timing plate has a different relative"zero" than the one you have. That's why there is a large difference between the notch and the sharpie mark.

Today I used my borescope to check the cylinders and I realized that I could use it to verify TDC too. So I checked the counterweight method, it's right on. I also redrew the cylinder#6 mark.

The cyl#1 mark was close, like a degree or two but the cylinder#6 mark was 8-10 degrees off... It's a good thing I was able to check that. If you care this is what you can see through the spark plug holes...


https://youtu.be/IVkuWjvRSlI
https://youtu.be/IVkuWjvRSlI

Also, I learned today that throttle body and intake cleaner spray will remove sharpie marks from the crankshaft pulley. 😎

[AugustneverEnds]

Since you are planning on replacing the rubber hoses under the intake I would recommend using silicone hoses, less prone to cracking over the long run. SpecialT has 'em: http://specialtauto.com/delorean-parts/cooling-system.html

Sorry I can't be of any more help than this! Good luck

[spikeygg]

There was a lot of coolant still in the system when I pulled the VOD coolant pipe. I'm wondering if I'm going to have a problem filling the system back up after reassembly. is there a way to "burp" the engine?

[Rich]

There was a lot of coolant still in the system when I pulled the VOD coolant pipe. I'm wondering if I'm going to have a problem filling the system back up after reassembly. is there a way to "burp" the engine?

How did we get to a VOD job from an engine miss? No answer needed....

Anyway, don't worry about finding a way to burp the engine before reassembing the cooling system. Filling with coolant then purging/bleeding the air is easily done no matter how the system gets put back together.

You will want to be sure to fill, bleed and then pressure-check your work before the intake manifold covers up the VOD hoses. Here is one reference for you to prepare with: http://dmctalk.org/showthread.php?12100. Go as far as you can in Post #3 by David T. without starting the engine, be sure the VOD hoses don't leak and the system holds 15PSI, then proceed to finish the job from there. Warm-bleed, if needed, can be done at the end.

[content22207_2]

Post #97. He had a leaking coolant hose under the intake manifold (biggest hose on the car). Intake manifold has to come off to remedy that.

Bill Robertson
#5939

[spikeygg]

So I put the VOD coolant pipe back in with new hoses and new O-rings, filled up the system and pressurized it with my new Mightyvac. The valley was dry but there was a little damp spot on the left head right next to where the water pump hose goes. There's apparently a flange there and a gasket. I dried it off and watched it and within a few seconds at 15.5lbs it became shiny again. Damn. I tried to tighten the bolts going to that flange and was able to move them a little but I couldn't get the shiny to go away completely.

If I want to replace this gasket, I'd rather not dump out half the cooling system into the VOD again. Is there a really good way to completely drain the coolant from the system (+engine)? I opened the petcock at the radiator and let it go for a long time, when it stopped the engine was still full of coolant. I opened that VOD coolant pipe and all the coolant dumped into the VOD. I'd like to avoid this from happening again if possible and if I can do it in a more controlled manner I'd be able to (cleanly) catch all the coolant and reuse it.

Well, I didn't have that gasket and I already filled up the system with another ~1.5 gallon of 50/50 so I'll leave it be for now it's a really slow leak anyway. While I was reassembling I grabbed the distributor cap and gave it a little jiggle, the springs on the side that attach it to the distributor base pulled it down and it snapped into place better than it was. Apparently, it was not completely seated... Anyway, the rest of the installation went well and I fired it up! I let it warm up a bit and checked the timing, as it stood the timing was set to 8°, I loosened the distributor and twisted it up to 13° and tightened it back down.

I still need to reset the idle speed but the timing mark/timing light is very stable and it sounds GOOD!

Thank you all for the help. Having your assistance made this work much easier.
-Greg

[Rich]

So I put the VOD coolant pipe back in with new hoses and new O-rings, filled up the system and pressurized it with my new Mightyvac.

If I want to replace this gasket, I'd rather not dump out half the cooling system into the VOD again. Is there a really good way to completely drain the coolant from the system (+engine)? I opened the petcock at the radiator and let it go for a long time, when it stopped the engine was still full of coolant. I opened that VOD coolant pipe and all the coolant dumped into the VOD. I'd like to avoid this from happening again if possible and if I can do it in a more controlled manner I'd be able to (cleanly) catch all the coolant and reuse it.

Glad to hear about the progress. Pressure-testing before getting the manifold back on is the way to go, as you see. Good that you found out before lots of driving - and coolant loss.

Answer to the question above, yes, to drain coolant from the engine unscrew both of the engine plugs. One plug on the outside of each cylinder bank. Left one is harder to get to. 8mm square socket, like the one used to open the oil drain plug, fits.

You may choose to skip that and live with the mess into the VOD since the amount of coolant above those gaskets isn't that much after you drain from a low pipe/hose and vent it (tank cap off and water pump bleed screw open). You did vent the system last time it got drained, right?

In any case a large towel stuffed into the VOD and beneath the hoses before you pull the water pump hoses off can suck up most of the mess as you pull things apart.

Question on the side: Looks like you might be putting silicone hoses in there - that's fine but are you also using the right hose clamps to go with silicone coolant hoses?

[spikeygg]

You did vent the system last time it got drained, right?

Question on the side: Looks like you might be putting silicone hoses in there - that's fine but are you also using the right hose clamps to go with silicone coolant hoses?

I did not vent the system. I'm not sure what that might be. Do tell...

I didn't opt for the silicone hoses, I got the standard rubber ones with the appropriate hose clamps.

[Rich]

I did not vent the system. I'm not sure what that might be. Do tell...

From Post #113, how to vent it:

You may choose to skip that and live with the mess into the VOD since the amount of coolant above those gaskets isn't that much after you drain from a low pipe/hose and vent it (tank cap off and water pump bleed screw open).....

Water pump bleed screw/valve is on rt side of water pump housing. Brass or SS.

[spikeygg]

Water pump bleed screw/valve is on rt side of water pump housing. Brass or SS.

I'm starting to think that I'm missing a bleeder screw on my thermostat housing... I just went out and took a picture of my thermostat housing:
44781

Would you please take a picture of your thermostat housing so I can see what this is supposed to look like?

[Rich]

I'm starting to think that I'm missing a bleeder screw on my thermostat housing... I just went out and took a picture of my thermostat housing

Sorry I mentioned it was on the water pump when it is really on the thermostat housing which sits on top of the water pump. Take another photo just a bit higher than the one you posted.

The first post in this thread shows where it is: http://dmctalk.org/showthread.php?8141-Is-this-my-water-pump-bleeder&highlight=thermostat+bleeder

[spikeygg]

The first post in this thread shows where it is: http://dmctalk.org/showthread.php?8141-Is-this-my-water-pump-bleeder&highlight=thermostat+bleeder

Nice, so I checked mine and it looks like I have a hose coming off of that nipple going to the overflow tank through a small return line tee. See attached photos, is this normal or not normal? I dunno...

44798 44799

[davidc89]

Nice, so I checked mine and it looks like I have a hose coming off of that nipple going to the overflow tank through a small return line tee. See attached photos, is this normal or not normal? I dunno...

44798 44799

This means the system will bleed itself

[content22207_2]

I just indexed the engine on my Volvo and discovered the timing scale is 1-2 degrees off:

45306

Don't know why, but the things do move around.

Bill Robertson
#5939

[David T]

I just indexed the engine on my Volvo and discovered the timing scale is 1-2 degrees off:

45306

Don't know why, but the things do move around.

Bill Robertson
#5939

1-2 degrees is not all that much and won't affect operation. Could be operator error. Are you using the same timing light? Put #1 cylinder at TDC and recheck your timing scale. Plug the vacuum line and make sure the mechanical advance is not sticking.

[content22207_2]

Could be operator error.

Oh please....

45308

For somebody who is normally Oorah about doing things by the book, you are surprisingly resistant to using the indexing feature Douvrin built into the PRV.

It's one of the few things I actually like about the engine.

Bill Robertson
#5939