Fuel Fuel Mixture Problems - Car won't start when mixture set properly [Archive] - DMCTalk Forum

spikeygg

08-28-2021, 05:05 PM

I busted out the dwell device and when the engine RPMs were bouncing around the dwell was stuck very low I can't remember the actual value but maybe 10 or something. I took out my Allen hex key and tweaked the mixture screw and the dwell came back up, when it did, the engine idle improved smoothing out drastically:

https://www.youtube.com/watch?v=fGIKN0bHLxw

I let the car idle for about 5-10 more minutes and shut it down with the mixture screw set so that dwell is good hot.

Now when I try to start the engine it won't fire up (hot or cold, I tried firing it up right after I shut it down and it won't even start up with the CSV "plug swap"). It's like I need a significantly enriched mixture for start AND cold idle and a leaned out mixture for hot idle. Is it possible that the cams won't allow the car to have a single fuel mixture balance point across temperature? If I can have a single fuel mixture balance point where should I start? If the accumulator is bad will the car be able to idle/run? What should I try to gather data and troubleshoot?

I've had lots of problems starting with this car because I can't seem to get it started and running without manually enriching the fuel mixture significantly.

Helirich

08-28-2021, 07:11 PM

Do you know if the warm up regulator is working?

Azar

08-28-2021, 07:48 PM

You have to operate the motor with the plugged hole where the CO adjuster is. Means you adjust it very slightly, then plug it and wait for 20 seconds untill the RPM settles. If not good, open, turn slightly again and plug it, wait 20 seconds, and so on.
Keep the plug always there.It sucks air through it.

spikeygg

08-28-2021, 07:55 PM

Do you know if the warm up regulator is working?

How can I tell? Not sure how to verify it's functional.

You have to operate the motor with the plugged hole where the CO adjuster is. Means you adjust it very slightly, then plug it and wait for 20 seconds untill the RPM settles. If not good, open, turn slightly again and plug it, wait 20 seconds, and so on.
Keep the plug always there.It sucks air through it.

Yes, I did that to get the car idling correctly. How can I get it to start (without having to adjust the fuel mixture)?

Helirich

08-28-2021, 09:09 PM

How can I tell? Not sure how to verify it's functional.

There are several ways. I would say the best way is with a fuel pressure guage. You check the "control pressure" cold and then again when it's hot. The WUR changes the control pressure as it warms up. It warms up via an electric element, but it will also warm up just from heat off the valve cover. (Just takes longer.)

I hope I got this straight in my head, but I believe when the control pressure is low, it runs richer. Then as the WUR gets hot, it raises the control pressure which makes the engine run leaner. It does this by closing a valve that is bleeding off pressure.

In any case, if that's your problem, you can get rebuilt ones or a rebuild kit. I got one off eBay. I wasn't very confident when I got done, but it works great.

spikeygg

08-28-2021, 09:16 PM

There are several ways. I would say the best way is with a fuel pressure guage. You check the "control pressure" cold and then again when it's hot. The WUR changes the control pressure as it warms up. It warms up via an electric element, but it will also warm up just from heat off the valve cover. (Just takes longer.)

I hope I got this straight in my head, but I believe when the control pressure is low, it runs richer. Then as the WUR gets hot, it raises the control pressure which makes the engine run leaner. It does this by closing a valve that is bleeding off pressure.

In any case, if that's your problem, you can get rebuilt ones or a rebuild kit. I got one off eBay. I wasn't very confident when I got done, but it works great.

Cool, I just bought this kit: https://www.amazon.com/BETOOLL-Injection-Pressure-Tester-Gauge/dp/B01L17TPT2/

I'm going to give it a try. Hopefully it's compatible, someone in the Q&A said they bought this kit for their DeLorean and it worked so ... fingers crossed. :D

Michael

08-28-2021, 09:58 PM

spikeygg

08-28-2021, 11:32 PM

Cammed cars can be tricky to set the mixture on but even set right, your car should not be behaving this way. Since it started before, and all you did was adjust mixture, I would look into the possibility you set the mixture wrong. When these cars idle for a long time, the probe can get some contamination on it because the EGT is not high enough. Dial the mixture back a little (opposite of what you did until it starts). After you set the mixture, take it out for a nice little drive. Get into the RPM's a bit. No road trip, just clear it's throat for a few miles to burn off any residue from the O2 probe.

Immediately after, check the Dwell again and zero in your mixture. Of course you will look for vacuum leaks just to make sure you are not compensating for unmetered air. A lot of the "old guard" will tell you idle surge is something that can't be corrected. On a properly running D, idle surge is non existent, even on a cammed car.

Once you are "back where you started" with the mixture, you can start diagnosing the fuel system. Primary pressure o rings in the FD come to mind, but that's just one of many possibilities(easy to check though).

I've been battling this starting/fuel problem since I got the car (around 2016). Years ago right after I got it I determined that the WOT microswitch was stuck on and the previous mechanic(s) that worked on it dialed back the mixture to compensate for the WOT switch being on all the time, I don't think they realized that was the root cause. I've since removed the WOT microswitch and the engine will only start if I dial up the mixture sometimes I have to use the CSV plug swap to make it start even with the enriched mixture. However, if I leave it like that and drive around, once the car is warm it bogs badly when taking off and stumbles a lot in low RPMs and idles similar to the 2nd video I posted: hunting around and never settling, nearly stalling out every 5-10 seconds. If I hop out and lean out the mixture, the car runs great from then on until I shut it down. It's a terrible loop and I'd like to fix it once and for all.

Also, I'm not sure you read the part about the dwell being pegged on the low end (too rich) and not cycling when the engine was hunting... it only started to cycle normally when I leaned it out which made the idle/throttle response much more normal. You're supposed to set the dwell while the engine is warmed up, right?

Michael

08-29-2021, 12:20 AM

Yes the mixture is set in closed loop. I think you have one or more problems and adjusting mixture is just a band aid fix. Mixture is the absolute last thing to set...after ALL other issues are resolved.

The thing is that a PRV running CIS can run well with a LOT of things out of whack. Vacuum leak, just adjust the mixture to compensate. Bad PPR Orings? Adjust the mixture. By the time that the ol standby fix of screwing with the mixture doesn't solve the problem, you got so much wrong that you don't know where to begin.

spikeygg

08-29-2021, 06:50 AM

Yes the mixture is set in closed loop. I think you have one or more problems and adjusting mixture is just a band aid fix. Mixture is the absolute last thing to set...after ALL other issues are resolved.

Yeah, I get it. That's not the first time I've heard this argument. However, I CANNOT get the car started and running without adjusting the mixture richer... unless you have a solution to make that happen without adjusting the mixture?

By the way, I have a CO monitor in the garage and this is what it looked like with the car running yesterday morning.
67087
You can see the back side come down about half-way, that was after I leaned out the mixture, got the car idling more favorably and the O2 signal finally cycling.

The blips later in the day were me trying to start it again (without any further mixture adjustments). It's a BIG garage with all exterior man doors (2), windows (2) and garage car doors (3) open.

Based on this chart from motor.com article: DIAGNOSING A LEAN-RUNNING ENGINE (https://www.motor.com/magazine-summary/lean-codes-january-2018/) CO gets worse as the engine runs richer:
67086

With it able to start, it's clearly too rich but with it tuned properly for hot operation it cannot be started.

I have the fuel pressure tester coming so I'll try that out and see if I can determine that the WUR is broken.

@Michael do you have modified cams in your car?

Michael

08-29-2021, 08:23 AM

Yeah, I get it. That's not the first time I've heard this argument. However, I CANNOT get the car started and running without adjusting the mixture richer... unless you have a solution to make that happen without adjusting the mixture?

By the way, I have a CO monitor in the garage and this is what it looked like with the car running yesterday morning.
67087
You can see the back side come down about half-way, that was after I leaned out the mixture, got the car idling more favorably and the O2 signal finally cycling.

The blips later in the day were me trying to start it again (without any further mixture adjustments). It's a BIG garage with all exterior man doors (2), windows (2) and garage car doors (3) open.

Based on this chart from motor.com article: DIAGNOSING A LEAN-RUNNING ENGINE (https://www.motor.com/magazine-summary/lean-codes-january-2018/) CO gets worse as the engine runs richer:
67086

With it able to start, it's clearly too rich but with it tuned properly for hot operation it cannot be started.

I have the fuel pressure tester coming so I'll try that out and see if I can determine that the WUR is broken.

@Michael do you have modified cams in your car?

Mine has cams. My car was acting very similar to yours. It progressively got harder and harder to start cold(would fire up but stall out almost immediately). I usually only had to restart it 2 or 3 times but then I was having to restart 7-8 times.

I too suspected the WUR and ordered one but I read on Dgo's site that they recommended a new FD and injectors at the same time. Not sure why injectors as they are either working or they are not and easy to test but since I did new injectors the previous year anyway, I just got the WUR and FD.

Replaced the WUR first since it was easiest and that was my hunch. It didn't help. The FD corrected my issue. After replacement, I had to lean my mixture out almost a full turn!

spikeygg

08-29-2021, 09:17 AM

Mine has cams. My car was acting very similar to yours. It progressively got harder and harder to start cold(would fire up but stall out almost immediately). I usually only had to restart it 2 or 3 times but then I was having to restart 7-8 times.

I too suspected the WUR and ordered one but I read on Dgo's site that they recommended a new FD and injectors at the same time. Not sure why injectors as they are either working or they are not and easy to test but since I did new injectors the previous year anyway, I just got the WUR and FD.

Replaced the WUR first since it was easiest and that was my hunch. It didn't help. The FD corrected my issue. After replacement, I had to lean my mixture out almost a full turn!

OMG, $700 for an FD rebuild +core! Is that how much you paid? I'm guessing Dgo you referred to is https://www.deloreango.com/? Why not buy from the official https://store.delorean.com if the price is so close?

Also, is there any way to test the Fuel Distributor? I'd hate to throw $700 at it and find out it was not the problem. :-/

Michael

08-29-2021, 09:35 AM

OMG, $700 for an FD rebuild +core! Is that how much you paid? I'm guessing Dgo you referred to is https://www.deloreango.com/? Why not buy from the official https://store.delorean.com if the price is so close?

Also, is there any way to test the Fuel Distributor? I'd hate to throw $700 at it and find out it was not the problem. :-/

Personally, I don't consider DMCH to be a benchmark of quality parts. I believe all the vendors make substandard parts in some areas(with DeLorean Industries being the possible exception). When I did mine, the FD was $640.00 when I bought it. The deciding factor in my case was with Dgo, my cores were to be returned after purchase and my core charge refunded. If I recall they even sent a call tag for shipping, not to mention Dgo offers free shipping. With DMCH I would pay shipping BOTH ways.

With DMCH, your old parts are sent to them to rebuild and sent back and I didn't like the idea of my car being apart and at their mercy for turn around time. Also DMCH was pretty clear that not all WURs were able to be rebuilt so I didn't want to again, be at their mercy.

I checked all I could with my limited knowledge. I had zeroed in on the WUR but turns out in my case the FD was the culprit(or maybe both?). I was willing to throw some money at it and hope for the best which thankfully worked.

That does remind me to ask if you removed the FD and checked the plunger operation? It should be butter smooth and not stick or grab in the least. Also check the primary pressure regulator for damaged or worn o rings. There is a kit that includes the 2 rubber rings and a new seal for a few bucks. May be worth a try because the orings can look good on the plunger but be hard and deformed. As cheap as they are it's not a bad idea to replace them every few years.

spikeygg

08-29-2021, 10:10 AM

That does remind me to ask if you removed the FD and checked the plunger operation? It should be butter smooth and not stick or grab in the least. Also check the primary pressure regulator for damaged or worn o rings. There is a kit that includes the 2 rubber rings and a new seal for a few bucks. May be worth a try because the orings can look good on the plunger but be hard and deformed. As cheap as they are it's not a bad idea to replace them every few years.

I have never pulled my fuel distributor off before. Is it easy to do for checking the plunger operation? Can I do it leaving all the fuel passages intact?

I just watched this video that explains the fuel distributor and injection flap (https://www.youtube.com/watch?v=K4BTagH8dfc), his plunger seems to move on its own! I think I see the o-ring on the bottom of the FD, looks like maybe a couple of inches in diameter. I'll have to poke around and see if I can find some example images or video of the primary pressure regulator o-rings because I'm not familiar with where those are... I don't suppose you have any pictures to share for that?

Thanks for the info -- having things to check is always good.

Michael

08-29-2021, 10:18 AM

I have never pulled my fuel distributor off before. Is it easy to do for checking the plunger operation? Can I do it leaving all the fuel passages intact?

I just watched this video that explains the fuel distributor and injection flap (https://www.youtube.com/watch?v=K4BTagH8dfc), his plunger seems to move on its own! I think I see the o-ring on the bottom of the FD, looks like maybe a couple of inches in diameter. I'll have to poke around and see if I can find some example images or video of the primary pressure regulator o-rings because I'm not familiar with where those are... I don't suppose you have any pictures to share for that?

Thanks for the info -- having things to check is always good.

Yes you can lift the FD off the metering assembly with all lines attached. The plunger is just a friction fit and it will fall out so be careful.

The primary pressure regulator is on the side. If memory serves, it's a 15mm and will come out as it's under sprung tension so make sure you remove the last few threads slowly and carefully. Also have a telescoping magnet handy to aid in getting all of the assembly out.

https://www.deloreango.com/pub/media/catalog/product/cache/image/1200x1200/e9c3970ab036de70892d86c6d221abfe/p/r/prim-press-regulator-1.jpg

Helirich

08-29-2021, 10:57 AM

On that PPV, when you remove the threaded end with the spring, don't walk away with those parts if the little cup stays in there. Some times residue pressure will pop it out after a few seconds/minutes. I recommend putting a rag to catch it or get it out immediately. If it pops out while you're not looking and falls down in the mess of tubes and hoses, you won't be happy.

Also, Michael is right about checking the FD plunger. Mine was stuck. I can't remember the exact symptoms, but ran poorly. I just pulled the FD with all lines attached and got the plunger loose by twisting it. That was the beginning of my car running good.

spikeygg

08-29-2021, 12:07 PM

Okay, I'm out here looking at it and it definitely looks like I need to break into the fuel lines to take the FD off the intake. Two of the screws are accessible but one is under a banjo bolt...

67088

Michael

08-29-2021, 12:13 PM

FWIW I just now watched the Dwell meter vid. You got no action going on there at all. When is the last time you changed the O2 sensor? Does the idle circuit work properly? That is something to address in the near future.

You may have to break that bolt and move the line to access the third screw. You should replace the seals once you break them loose but for testing purposes, just retighten and make sure they don't leak after you check the plunger.

I don't know why they used standard screws on the FD. If they are hard to break loose, don't force it. Put a little PB blaster on it and if that doesn't work use an impact driver(the hand tool if you have it but hit it lightly because the FD can crack).

spikeygg

08-29-2021, 12:26 PM

I took that top hose off and was able to slightly lift the FD. The plunger seems to be very smooth but I can't lift the FD high enough to assess the o-ring status. The screws holding the FD on were fairly loose. The o2 sensor is brand new.

Ron

08-29-2021, 12:33 PM

FWIW I just now watched the Dwell meter vid. You got no action going on there at all. I was thinking the same thing. It seems it only reacts when the throttle is hit and even then it fluctuates in a range way above 20 (while it clears out).
I'm thinking hang on to the parts money until the pressures are checked, then set the CO and go from there. ...then tweak it a little off spec to compensate for the cams if needed.

spikeygg

08-29-2021, 12:52 PM

I asked my girl to come handle the camera while I held the beast up so I could get a good view of it. Here's the result:

67089

It's pretty grungy under there. The plunger is quite loose and wants to drop out as I lift the distributor up. I noticed it has a couple of spots on it (looks like rust?) but dunno if that's an issue or not. I'd like to clean all the dirt off but I'm worried about wiping it into the intake since I can't just move the distributor out of the way. For now I put it back down, buttoned it all up, and keyed on to run the pump a few times. When I get the pressure tester, I'm hoping I'll have a better idea of how stuff looks.

EDIT: Haha, I guess this stupid dmctalk forum thought it would be better if the picture was upside down. :-/ The pictures I took were the other way 'round.

David T

08-29-2021, 03:15 PM

If the plunger can move freely without sticking LEAVE IT ALONE! Assuming the car ran OK before your problems my guess is a vacuum leak (or leaks). You tried to "fix" it by adjusting the mixture and that got it to run better but only at idle. After-market cams make the motor even more sensitive to vacuum leaks, especially at idle since you don't produce much vacuum at idle. Because of the vacuum leaks you lean out once you go off-idle and the adjustment you did won't help. You ONLY touch that idle screw once you KNOW there are NO vacuum leaks and everything else is perfect. The mixture only changes because you get vacuum leaks, not because the adjustment changed.

spikeygg

08-29-2021, 04:53 PM

Where should I hook up the fuel pressure tester? Do I put it in line between the fuel filter and fuel distributor?

Ron

08-29-2021, 05:36 PM

FWIW, instructions should come with the gauge.

67090

spikeygg

08-29-2021, 05:46 PM

FWIW, instructions should come with the gauge.

67090

Thanks @Ron! That's what I needed. The instructions that came with the thing are terrible... I'm pretty sure this was written by Chinese. :dead:

spikeygg

08-29-2021, 07:16 PM

Okay, with the tool I bought I was only able to measure the pressure at a single point (instead of running it in-line). It came with a bunch of fittings but none of them worked for putting the device in-line. So, all I was able to get was the pressure at the top of the fuel distributor that goes to the CPR during engine operation. It was static at 45psi, slightly over 3bar, I hooked up the dwell meter and it was static at ~8º (engine cold). I revved it periodically to help keep the exhaust temps up until it was warmed up and then the dwell meter ran like this:

https://www.youtube.com/watch?v=U5HJFLTecH4

When I keyed the engine off, the pressure at the top of the distributor bled down very quickly: from 45psi to 0psi in about 15 seconds. So, clearly there's a leak somewhere, but it isn't on the outside of the engine because I didn't see or smell fuel anywhere.

What's the best way to determine where the leak is coming from?

Should the top of the FD be fixed at 45psi?

Where should the dwell meter oscillate? If I'm reading the workshop manual correctly 35º-45º, is that like this:
67091

I think I'm going to return this pressure tester and try to get a kit that I can mount in-line because I want to be able to shut off the return feed and get the max pressure, like it showed in Ron's attachment.

Ron

08-29-2021, 10:36 PM

Okay, with the tool I bought I was only able to measure the pressure at a single point (instead of running it in-line). It came with a bunch of fittings but none of them worked for putting the device in-line. So, all I was able to get was the pressure at the top of the fuel distributor that goes to the CPR during engine operation. It was static at 45psi, slightly over 3bar, I hooked up the dwell meter and it was static at ~8º (engine cold). I revved it periodically to help keep the exhaust temps up until it was warmed up and then the dwell meter ran like this:

When I keyed the engine off, the pressure at the top of the distributor bled down very quickly: from 45psi to 0psi in about 15 seconds. So, clearly there's a leak somewhere, but it isn't on the outside of the engine because I didn't see or smell fuel anywhere.

What's the best way to determine where the leak is coming from?

Should the top of the FD be fixed at 45psi?

Where should the dwell meter oscillate? If I'm reading the workshop manual correctly 35º-45º, is that like this:

I think I'm going to return this pressure tester and try to get a kit that I can mount in-line because I want to be able to shut off the return feed and get the max pressure, like it showed in Ron's attachment.

Connecting your gauge to the top of the distributor is the same as shutting the valve on the correct type of gauge. That should show primary pressure ("max pressure"). It should be 71-79 psi (WSM D:02:01). I would double check then suspect the PPR. ...If you still have no rest pressure after fixing that, I would suspect the accumulator.
Also, note that there is another o-ring in the PPR not shown in the pic above (which does not come in some of the 'warm up repair kits').

For dwell, you need to use the 8 cylinder scale and divide by 2...so it should oscillate across 20º, on eight cylinder scale.

spikeygg

08-29-2021, 11:03 PM

Helirich

08-30-2021, 09:54 AM

I'm sure that kit can be hooked up to read both. I have one similar. I have to admit, mine is Chinese junk, but it works somewhat.

Anyways, it looks like you are reading control pressure right now. It's been awhile since I did this, but 45 psi control pressure when cold I think is OK. Does it go up some when warmed up? It would really be nice if you could read max pressure before you remove the PPV. I don't like disturbing that because it's easy to cut the O-ring when installing it. If you are determined to remove the PPV, have some spares. Those O-rings are metric and difficult to find.

spikeygg

08-30-2021, 10:52 AM

I'm sure that kit can be hooked up to read both. I have one similar. I have to admit, mine is Chinese junk, but it works somewhat.

Hey, if I take a few detailed pictures of the kit would you help me to figure out which fittings to use where? I'd love to not have to return this kit if it will work for both readings but, for the life of me, I cannot figure out how to use it to get both readings.

The biggest problem with this kit is that the ends of the piece that has the valve in it has female threaded ends, and they are different thread patterns! The kit only has like 1 or 2 fittings in it that will thread into those sockets... It seems impossible.

Helirich

08-30-2021, 11:31 AM

Hey, if I take a few detailed pictures of the kit would you help me to figure out which fittings to use where? I'd love to not have to return this kit if it will work for both readings but, for the life of me, I cannot figure out how to use it to get both readings.

The biggest problem with this kit is that the ends of the piece that has the valve in it has female threaded ends, and they are different thread patterns! The kit only has like 1 or 2 fittings in it that will thread into those sockets... It seems impossible.

Yea, take a pic. I do remember that I had to hook it up kind of "round a bout". They didn't make it easy. I believe one end threaded directly into the WUR. Then the other hooked to the fuel line that I removed from the WUR. So it put the guage in between.

Ron

08-30-2021, 11:49 AM

@Ron, the stock fuel circuit was still complete with the gauge installed. I used the gauge set's banjo bolt replacement that added a quick disconnect for the gauge so it shouldn't be with the valve shut.Ah, you did have it in-line...So no, it shouldn't be a set pressure. It should read ~20psi cold, ~33psi @ 70F, and ~45 psi warm (WUR/CPR temps). The exact temps-pressures are in the chart on the same page in the WSM I posted above.

spikeygg

08-30-2021, 08:37 PM

Yea, take a pic. I do remember that I had to hook it up kind of "round a bout". They didn't make it easy. I believe one end threaded directly into the WUR. Then the other hooked to the fuel line that I removed from the WUR. So it put the guage in between.

@Helirich, here's a couple of pictures I snapped of the equipment:
67099
67098

I took a picture of the only piece in the kit with a valve and it has two female threaded ends on it. I put a green box around the only piece (banjo fitting) that will thread into that end with the tighter threading. Sorry about the sizes of these pictures, they were much larger until I uploaded them to this forum. The size literally went from 3.45MB to 125KB. Let me know if you want more detail.

Ah, you did have it in-line...So no, it shouldn't be a set pressure. It should read ~20psi cold, ~33psi @ 70F, and ~45 psi warm (WUR/CPR temps). The exact temps-pressures are in the chart on the same page in the WSM I posted above.

Yeah, that's good to know. I'm pretty sure that the fuel pressure was 45psi right off the bat so indications are that my WUR may be bad/unable to regulate the warm-up pressure which makes sense with my symptoms. Set fuel mixture close to correct for cold engine is way too rich for driving (never gets leaned out by WUR) and set fuel mixture correct for driving is too lean for cold engine and starts (because the fuel never gets enriched by the WUR). I'm going to double check that is how the car responds.

If it does operate that way, do you concur? Does that point to my WUR being bad?

Helirich

08-30-2021, 09:21 PM

That does look like my kit, but I will double check tomarror.

On the WUR, if you remove the incoming banjo, (towards the front of the car) there could be some fine copper screens Jamed down the hole. If you remove them with a pic, you may find them clogged. I kind of destroyed mine, so I left the out. I didn't get new ones with the rebuild kit, but it's been running fine so far. If they are clogged, you will have high control pressure and lean conditions.

Ron

08-31-2021, 09:18 AM

Yeah, that's good to know. I'm pretty sure that the fuel pressure was 45psi right off the bat so indications are that my WUR may be bad/unable to regulate the warm-up pressure which makes sense with my symptoms. Set fuel mixture close to correct for cold engine is way too rich for driving (never gets leaned out by WUR) and set fuel mixture correct for driving is too lean for cold engine and starts (because the fuel never gets enriched by the WUR). I'm going to double check that is how the car responds.

If it does operate that way, do you concur? Does that point to my WUR being bad?Yep, that's the way it should operate -- The WUR is fed primary pressure, which is constant, and it dumps extra pressure to the port on the FD that goes back to the tank to vary the control pressure.
...If you read good primary pressure AND always get 45 psi control pressure, the WUR is the main suspect. It could be toast or have a partial blockage anywhere from its input port to the tank.

(If its screen is clogged (totally blocked), the control pressure would match primary pressure. If the screen is missing, odds are that trash is preventing it from raising the pressure and you are adjusting the CO screw to compensate...assuming it is always 45 psi. Or it may just be bad.)

As you probably guessed, without knowing the primary pressure, the other readings are about useless.
(Swap gauges while you can return the set you have ;-)

Helirich

08-31-2021, 11:50 AM

OK, I looked at my kit and it seems to have all the same pieces, but they are not arranged the same. In any case, one thing I noticed right away is I have an adapter threaded in one end of the long tube. I must have left it there from my last use.

Here is a pic of how I think I had it. The right side has an old fuel line in it to show you how it's hooked. The left side would thread in your WUR. Right side would have the line you removed from the regulator in place of my old fuel line.

67100

I hope you can see (3) fittings on my gage hose. I believe those three fittings are in your box in these locations.

1. Male to female - second row, first fitting.

2. Banjo to male threads- third row, third or forth fitting. Next to your circled fitting.

3. Male to male- first row, last (or seventh) fitting.

Hope this helps

spikeygg

08-31-2021, 10:23 PM

OK, I looked at my kit and it seems to have all the same pieces, but they are not arranged the same. In any case, one thing I noticed right away is I have an adapter threaded in one end of the long tube. I must have left it there from my last use.

...

Thanks for the detail Helirich, I took a very close look at my set again following your instructions and the problem I have is that on my hoses that have the valve the ends are two different threadings. I grabbed all the pieces you listed and put them on the carpet in this picture:

67103

The only fitting that I can thread into that hose end is the one at the end of the squiggly arrow. You can see that the other three fittings have a different thread pitch, they only thread into the female side by two threads and get stuck. I just pulled the banjo from the top of my WUR to see if it would thread in and the diameter is too small.

I wonder if both the hose ends on your valved hose have the same threading on both ends -- I think if mine had the same threading I could use it like you're describing.

Helirich

09-01-2021, 09:36 AM

Thanks for the detail Helirich, I took a very close look at my set again following your instructions and the problem I have is that on my hoses that have the valve the ends are two different threadings. I grabbed all the pieces you listed and put them on the carpet in this picture:

67103

The only fitting that I can thread into that hose end is the one at the end of the squiggly arrow. You can see that the other three fittings have a different thread pitch, they only thread into the female side by two threads and get stuck. I just pulled the banjo from the top of my WUR to see if it would thread in and the diameter is too small.

I wonder if both the hose ends on your valved hose have the same threading on both ends -- I think if mine had the same threading I could use it like you're describing.

My hoses have differnt threads also. I remember now that I really had to tighten one of the fittings to get it to stop leaking. Maybe it was slightly differnt threads. Maybe that's why I left it together. The whole thing is chinease junk. But I got it to work.

Ps, that wasn't the only problem I had. One of the "quick disconnects" sometimes would not let pressure through. I think the shrader would get stuck. I was all set to buy a new one when I got my car running good. The problem with them is they all look the same. Hard to verify where they are made. I was just going to buy a more expensive one and hope for the best.

Helirich

09-01-2021, 09:47 AM

Looking at your pic, the two bottom fittings go in the hose ends. It looks like the two male ends you have touching are slightly differnt. Then one of your two banjo fittings should go in the female side of those adapters. And the other male should go in the WUR.

dmcman73

09-01-2021, 10:49 AM

My hoses have differnt threads also. I remember now that I really had to tighten one of the fittings to get it to stop leaking. Maybe it was slightly differnt threads. Maybe that's why I left it together. The whole thing is chinease junk. But I got it to work.

Ps, that wasn't the only problem I had. One of the "quick disconnects" sometimes would not let pressure through. I think the shrader would get stuck. I was all set to buy a new one when I got my car running good. The problem with them is they all look the same. Hard to verify where they are made. I was just going to buy a more expensive one and hope for the best.

67104

The blue items circled connect to each other and then you remove the fuel line from the WUR (the one leading to the center of the distributor) and you connect the fuel line to the brass adapter using the banjo bolt and crush washers.

The red items, you thread one of the brass fittings into the WUR (where you removed the fuel line) and then attach the other threaded side of the brass fitting to the hose. You must make sure that the valve on the pressure tester is on the WUR side or you won't be able to take the proper readings.

spikeygg

09-03-2021, 10:25 PM

dmcman73

09-04-2021, 06:46 AM

So, I pulled my warm up regulator out today and I can see that there's junk in one of the ports (the one with the screen). How do I go about cleaning that gunk out?

67111

Also, I pulled all my injectors but I can't seem to get the bushings off of them. Anyone know how to get those bushings off the injectors?

67112

Use a sharp pick and pop each screen out, they are just pressed into the ports. There are a number of screens on there, so be careful.

Are you planning to reuse the seals? The seals can bind to the injectors, spray some WD40 on the seals and a little on the body of the injector below it , then you can use a pair of pliers to gently squeeze the seals and try and rotate the injector in it with an open end wrench.

Replace the seals, though, don't reuse them.

Azar

09-04-2021, 07:15 AM

I sent my injectors for testing, they were all bad. So I just brought new plus new seals. They are very tight fit and easily to be damaged ....

Helirich

09-04-2021, 08:24 AM

Ron

09-04-2021, 12:46 PM

So, I pulled my warm up regulator out today and I can see that there's junk in one of the ports (the one with the screen). How do I go about cleaning that gunk out?

67111

Also, I pulled all my injectors but I can't seem to get the bushings off of them. Anyone know how to get those bushings off the injectors?

67112
If carb cleaner won't clean the screen up, use a pick to remove them. A lot of people flush the line and leave them out since they are down stream from the filter. You can find fine mesh woven brass screen on eBay, just don't go too fine...

Just cut the injector seals off since they need to be soft and are only $3.13 ea (http://If carb cleaner won't clean the screens up,).

spikeygg

09-25-2021, 08:13 PM

Well, I sent my injectors off to be cleaned and got a replacement WUR from SpecialTAuto and installed everything today. After I reinstalled everything I got the car running by playing with the mixture, warmed the engine up and then dialed in the mixture so the dwell oscillation was around 20°-25° on the 8-cyl readings. It was pretty good and hot when I shut it down and the engine was idling great. I then let the car sit for most of the day to cool down so I could get a cold start in and see if it fixed my problem but the issue persists.

:mallet:

If I do the plug swap I can start the engine but it runs rough and it sounds like nothing is coming from the left bank of cylinders, when I unplug the cold-start injector I hear the left bank of cylinders start firing and after a few seconds of that, the engine dies. I just tried starting it over and over again in the garage just now, probably got it started 6 times using the plug swap and every time it was that same situation... without plug swap it just cranks and doesn't fire sometimes a small stumble.

Ron

09-25-2021, 09:01 PM

Not sure, but it sounds like you're still setting the CO while it was cold. Did you check it (with the plug in place) while it was "good and hot"?,

spikeygg

09-25-2021, 09:30 PM

Not sure, but it sounds like you're still setting the CO while it was cold. Did you check it (with the plug in place) while it was "good and hot"?,

Is CO the same as the mixture screw? Once I set the mixture screw to 20°-25° with the engine good and hot I left it. I'd like to get this thing running without having to mess with the mixture but thus far I'm unsuccessful.

Ron

09-26-2021, 04:43 AM

Is CO the same as the mixture screw? Once I set the mixture screw to 20°-25° with the engine good and hot I left it. I'd like to get this thing running without having to mess with the mixture but thus far I'm unsuccessful.Yes (CO is symbol for Carbon Monoxide ).
Since it is swinging 20°-25°, hot, I would think it is close enough for now.
Maybe try pulling the plug wires one at and record which ones that don't seem to make the engine sound different or change the RPM. (If it has performance cams, you might have to do this at a high in order to hear any difference.)

Bitsyncmaster

09-26-2021, 04:47 AM

I would check the control pressures with the new WUR. If that is good the only thing left is the fuel distributor.

Ron

09-26-2021, 02:57 PM

I would check the control pressures with the new WUR. If that is good the only thing left is the fuel distributor.+1..it would be odd to be only on one bank, BUT a good excuse for a 6 pak of beer (bottles to compare the fuel delivery to each cylinder).

Michael

09-26-2021, 06:15 PM

I too suspected the WUR and ordered one but I read on Dgo's site that they recommended a new FD and injectors at the same time. Not sure why injectors as they are either working or they are not and easy to test but since I did new injectors the previous year anyway, I just got the WUR and FD.

Replaced the WUR first since it was easiest and that was my hunch. It didn't help. The FD corrected my issue. After replacement, I had to lean my mixture out almost a full turn!

Ahem. Post #13 on this thread over a year ago.

spikeygg

09-26-2021, 06:34 PM

Ahem. Post #13 on this thread over a year ago.

Yes, don't think I haven't been thinking about that post as I work my way through the money like you did. I'm likely to end up there too. :( If I do buy the FD, I REALLY hope that solves it. This is F'n annoying.

Michael

09-26-2021, 06:51 PM

Yes, don't think I haven't been thinking about that post as I work my way through the money like you did. I'm likely to end up there too. :( If I do buy the FD, I REALLY hope that solves it. This is F'n annoying.

I admit it was a shot in the dark but I just thought to myself that the FD is the most complex(mechanical) part of the fuel system and the more complex, the more prone to failure. I had checked and diagnosed everything my limited knowledge allowed me to (and replaced the injectors/seals/WUR). I just threw a bunch of money at it and it worked.

I guess this was about 2 years ago and I have to admit the excitement and terror of walking to my car among a crowd of onlookers wondering if it will start is gone. It's been replaced by the boring monotony of having a car start no matter how long it sits and idles perfectly. Almost takes the adventure element out of owning a DeLorean.

spikeygg

09-26-2021, 07:09 PM

I guess this was about 2 years ago and I have to admit the excitement and terror of walking to my car among a crowd of onlookers wondering if it will start is gone. It's been replaced by the boring monotony of having a car start no matter how long it sits and idles perfectly. Almost takes the adventure element out of owning a DeLorean.

LOL, I don't dare drive my car anywhere with it operating like this. I guess I could if I have my 3mm Allen wrench with me but I really don't like changing the mixture just to get the thing started and then tweaking it again to keep it running right. Anyway, I ordered a different fuel pressure testing kit from Amazon (https://www.amazon.com/gp/product/B008FJXA3M) this one has comments on it from DeLorean owners saying that it works for measuring both values. When it gets here I'll take some pressure measurements like Dave suggested and then, if nothing is awry, likely pull the FD and send it in for replacement.

dmcman73

09-28-2021, 10:32 AM

LOL, I don't dare drive my car anywhere with it operating like this. I guess I could if I have my 3mm Allen wrench with me but I really don't like changing the mixture just to get the thing started and then tweaking it again to keep it running right. Anyway, I ordered a different fuel pressure testing kit from Amazon (https://www.amazon.com/gp/product/B008FJXA3M) this one has comments on it from DeLorean owners saying that it works for measuring both values. When it gets here I'll take some pressure measurements like Dave suggested and then, if nothing is awry, likely pull the FD and send it in for replacement.

Just make sure when you hook it up, the hose side with the valve on it (coming off the "T") should connect to the WUR port. Otherwise you won't get the right results when you open/close the valve to test primary and control pressure.