Chugging, hard start, dies on acceleration... you tell me.

[LoveThySpatula]

Back again to boggart you guys again for information. Please be gentle, I'm still new at this.

First a tad bit of history on what is going on...

I had the hot start issue confirmed by myself and a friend that the fuel system was not holding pressure and due to my limited resources, I decided to replace the accumulator and check valve. At that point I had already received an accumulator and had the check valve on order (2-ish weeks until delivery - go figure) so I prompted to put the new accumulator in. Other than the R&R being a total pain in the butt, it went in without anything breaking. Since I have driven the vehicle many many times without issue since I picked it up, and after I replace the accumulator, I figured there would be no problem taking it down to the local good guys car show - a solid 75 mile drive in one direction. She started up and drove great all the way to my parents' place then great all the way to the car show. Bear in mind this was all in about 85° - 90° heat.

We parked the car and went the the show, great show really, lots of cool stuff. Almost too much to see with some 2500 cars there, but I digress...

We decided to leave about 4 hours later and came out to the DMC and she had a VERY hard time starting. Like I've never had a "cold" start be so hard to start. We had to do the plug swap method just to get it started cold - I couldn't believe it. Then it got really good. Driving out of the parking lot (engine appeared to be idling fine, minor accelerations were ok) and onto the road, I attempted to accelerate and it just falls flat on its face. There was nothing, nothing at all. I gave it gas and it started chugging like it was going to die, almost like it was getting no fuel. It would idle into gear but would do nothing but chug and sputter under load.

Long story somewhat less long, had to have it towed to my parents' place up the road. A week later I received the check valve (unrelated I'm sure) and a new fuel filter. Replaced the pair of them and low and behold, she ran and accelerated - still had a very hard start, had to do the plug swap. The next day... nothing, again. At about 15% throttle or less it will rev, but anything above that and it just chugs and sputters until it dies - hot or cold. It seemed to have happened all of the sudden and, suspiciously, it happened while my car was sitting at the car show. I had figured a clogged fuel filter was the culprit here or possible faulty accumulator, but now I'm not sure where to start. I also checked the plug wires and coil wiring for possible faults and found nothing.

Anyone have any ideas?
Thanks, again, in advance.

[Bitsyncmaster]

First thing to check is the fuel mixture. Maybe your prevous owner adjusted it with the bad accumulator and plugged fuel filter. Now that those are fixed the mixture may be off. Don't know why it would drive that 75 miles fine and then act up after that.

[Denverdelorean]

Check for vacuum leaks. That's all I got to start.....

[Kozmatic]

Did you run it low on fuel? Do you know if the tank was thoroughly cleaned out? I’m wondering if something got up in there.

[LoveThySpatula]

I thought about the fuel mixture being off but that wouldn't explain why it acted up out of the blue. I know there is a minor vacuum leak and the only thing I can think of regarding a leak is that something got sucked in. I believe the tank has not been cleaned out, but due to a partially faulty fuel gauge, I always fill it up before I go anywhere.

[Kozmatic]

I thought about the fuel mixture being off but that wouldn't explain why it acted up out of the blue. I know there is a minor vacuum leak and the only thing I can think of regarding a leak is that something got sucked in. I believe the tank has not been cleaned out, but due to a partially faulty fuel gauge, I always fill it up before I go anywhere.

It's pretty easy to pull the fuel pump and have a look at the screen and see if it looks bad. Also, you can disconnect the output hose and run a temp fuel hose into a 5 gallon bucket and jump the RPM relay, get that fuel pump running and see what the flow looks like.

RPM jumper for fuel pump: http://dmctalk.org/showthread.php?1155-How-To-Jump-the-RPM-Relay

[NightFlyer]

Sounds like you may have a few unrelated issues going on simultaneously.

First thing's first - you need to determine if you truly have a cold start problem or if it's actually a hot start problem.

In hot sunny weather, hot start problems can be prevalent even after rest/off periods upwards of 5+ hours - especially if the car is parked in the sun the entire time on a hot surface, such as asphalt, blacktop, etc.

If you can't get the car to start from cold (and you're certain it's cold and not hot) without doing the plug swap trick, then it suggests either a faulty or unplugged TTS (thermotime switch) or there's a problem with the 12V feed on the CSV's plug. If you're sure that you're having a true cold start problem, then you'll have to test the 12V feed on the CSV's plug and if that's good, then you know that you have a bad or unplugged TTS, and it will need to be replaced. If you're not getting 12V on the plug's feed while engaging the starter, then you'll need to determine why and remedy the situation that's preventing such.

As to your running problem, check to make sure that all your vacuum lines are secure and aren't leaking. Check the air induction system for any leaks by using targeted sprays of carb/throttle body cleaner while the engine is running. Also spray around the lower half of the mixture unit (by the idle air motor's intake tube - aka the pipe of agony). If you find nothing, check the operation of vacuum systems affecting fuel and spark - namely the WUR/CPR and the electrical distributor's vacuum advance for proper operation.

It works like this:

When you first start the engine cold, vacuum from the multi-port switch in the y-pipe (under the intake) is directed to the warm-up regulator / control pressure regulator (WUR/CPR). Once the running temperature reaches 104F, the multi-port switch redirects the vacuum to the solenoid hanging off the mixture unit behind the fuel distributor. When the engine is idling, the idle micro-switch is activated (closed) and instructs the solenoid to hold the vacuum there within the solenoid. When the the engine is under throttle, the idle micro-switch is disengaged (open) and causes the solenoid to actuate and release the vacuum being held there onward to the distributor in order to cause the vacuum advance of the timing.

To confirm operation, you simply pull the vacuum lines off the WUR/CPR and the electrical distributor's vacuum chamber and/or vacuum solenoid and check for the presence/absence of vacuum during the various stages of engine operation.

If you find nothing wrong, we'll continue to diagnose and eventually get it figured out :thumbup:

[Jonathan]

Just to add to the comment about easily/quickly checking the suction side of the fuel pump... your pick-up hose might have gotten pinched or collapsed for one reason or another and the pump can't suck up enough fuel to run the engine properly. Sort of like sucking through a straw too strong and it flattens. Our cars came with a fuel warming feature... ya know, cause fuel has such a high freezing point and all. The pick-up hose might have gotten hot enough to squish itself flat or if you had already been in there and moved the fuel pump in some manner, when you reinstalled, it might have now put the pick-up hose bent up against the side or bottom of the tank. Worth a check anyway.

[Bitsyncmaster]

All good suggestions. It also reminded me of one fault I had. I was running "John's" power pump which has a smaller dia. than the stock pump. So the pump had a foam spacer to hold it in the bracket. Well that foam spacer failed and let the pump twist. It tore my pickup hose so the engine stopped but I could see it just twisting the hose so you would get very limited fuel flow.

Since your problem happened suddenly, I'm thinking like the others that your problem may be in the tank.

[David T]

All good suggestions. It also reminded me of one fault I had. I was running "John's" power pump which has a smaller dia. than the stock pump. So the pump had a foam spacer to hold it in the bracket. Well that foam spacer failed and let the pump twist. It tore my pickup hose so the engine stopped but I could see it just twisting the hose so you would get very limited fuel flow.

Since your problem happened suddenly, I'm thinking like the others that your problem may be in the tank.

Check the pick-up hose in the tank and make sure the frequency valve is buzzing. Tale the plug off and put it back on a couple of times.

[LoveThySpatula]

Thank you all for your suggestions, I will be delving in deep into this issue this weekend (or when I find the time) and I'll get back to you all with updates.

And thank you all for being very helpful, especially to accommodate a newbie!

The fuel pickup tube may actually be the cause because I know that the pump has been fiddled with due to the dust cover being all funky and installed improperly - that will be where I will start.

As to there being multiple problems at once... I'm almost certain this has something to do with it, but I'll be starting with a solid fuel pump and line inspection.

[LoveThySpatula]

Finally got some time to work on the car - they've been working us to death at the People's Republic of Boeing.

I've found nothing wrong with the fuel system - pulled the pump and checked it out. Everything looked ok, no pinched or collapsed hoses. Bottom of the tank looks clean enough - couldn't access the screen though due to the tank being full. Maybe I'll run it low and check it.

Anyways, I found a nasty vacuum leak around the tubes that go from the throttle to the manifold and, get this, the bolts were loose! I tightened them up and the leak was lessened, however, it's still leaking. I'll be ordering some new gaskets and replacing those - hopefully that takes me one more step in the right direction.

Side note - she started up very easily after sitting in the garage for six days. Got her all warmed up and shut her off just to test the hot start deal. Still has a hot start issue as well - I'm hoping the gasket may have something to do with it but I'll keep you guys posted.

[LoveThySpatula]

Well guys got the new "intake" gaskets installed and the vacuum leak seems to have subsided for the most part. The no acceleration issue seems to have been unaffected.

I'll be following nightfire's advice regarding checking the WUR / CPR system for issues.

I did find another odd item that may or may not be related. It appears that my injectors are loose - they all have a slight amount of play in them. I will be tightening these down slightly to see if anything changes.

Last question of the day... Would a faulty ignition coil possibly be giving me these issues?

Thanks

[NightFlyer]

I did find another odd item that may or may not be related. It appears that my injectors are loose - they all have a slight amount of play in them. I will be tightening these down slightly to see if anything changes.

Last question of the day... Would a faulty ignition coil possibly be giving me these issues?

Thanks

Not sure what you mean by "the injectors are loose," whereby tightening them down would resolve the issue. The injectors are held in the bungs via a rubber boot and metallic clip. If either are bad, it can result in a vacuum leak around the injectors. To check, spray your targeted blasts of carb/throttle body cleaner at the injectors while the engine and run and note any surges in engine RPM resultant of doing so.

It's possible that your problem is ignition related, but highly improbable. As Dave Swingle likes to say, it's usually a fuel problem with our cars. That said, it doesn't hurt to confirm spark (you want a nice blue arc, as opposed to a yellow or white arc), and pull and plug and check it to get a read on what's going on inside the combustion chamber.

First, confirm that you truly don't have any more vacuum leaks (and especially around the injectors). Then, confirm the operation of your vacuum systems - both WUR/CPR and ignition distributor advance. Next, pull the fuel lines off the WUR/CPR and inspect, clean the filtration screens as is necessary. After, confirm spark while the engine is running, and after shutting it down, pull a plug and see if you can't get an idea of what's going on in the combustion chamber that might help us better zero in on the offending culprit.

It's also possible that your fuel accumulator suffered a very rare complete failure, but that's also highly improbable.

You can test the accumulator if you so desire by pulling the rear relief hose off the accumulator's barbed fitting, blocking off that hose, sticking a piece of loose hose on the barb (doesn't have to be a tight fit) and running the other end to a small bucket/catch container. Then jump the fuel pump on for roughly a minute or two. If the accumulator is fully functional, no fuel should come out of the barb/hose. If the accumulator is worn but still functional (although not as good as new), you may see a few drops/dribbles of fuel, but nothing dramatic. If the accumulator has suffered a complete failure (rare), then you'll experience a steady stream of fuel coming out the hose/barb, in which case, you'll need to replace the accumulator with a new one.

So, that's the order in which I'd start trouble shooting things,

We'll then go from there.

Don't make the mistake that most owners do and throw new parts at the problem until something sticks/works. Actually take the time/effort to diagnose the problem properly, and then you can get it fixed without otherwise spending money on a bunch of parts that you really didn't actually need.

Best luck :thumbup:

[LoveThySpatula]

Thanks for the info nightflyer.

What you say about the injectors makes sense... I wasn't sure how these are mounted thus my curiosity.

I'm fairly certain the ignition system is good, I checked everything out - good spark, everything is plugged in, spark plugs look great. I checked everywhere for more vacuum leaks (at idle it revs high then low rinse, and repeat - typical vacuum leak symptoms) but was unable to find any. I had the motor running and was taking off the airbox when I remembered I forgot to check out the frequency valve from a previous suggestion. I unplugged it while the car was idling and all of the sudden the idle cleared up and the motor was able to rev, even at wide open throttle. Now I thought this may have been related to the fact that the motor had warmed up so I drove it around for about a half hour then parked it for about two hours. Came back out and it seems to be doing well - still has a hot start issue but it appears the frequency valve may be faulty...

Will the vehicle be ok to drive without the frequency valve connected? Could this valve cause my peculiar running condition?

Thanks much.

[NightFlyer]

Frequency valve is a part of the lambda system, the purpose of which is to balance out the AFR so as to reduce emissions and provide maximum fuel efficiency. The frequency valve controls line pressure in the fuel distributor via instructions it receives from the lambda ecu, which operates in a fixed (open loop) or dynamic (closed loop) program mode. In closed loop operation, the ecu interprets signals it receives from the O2 (oxygen) sensor, which takes readings of the exhaust stream from its mounted location within the exhaust pipe.

The fact that you're idling and running fine without the frequency valve functioning at all suggests that your CO/AFR adjustment is set to run rich.

If you still have a catalytic converter as a part of your car's exhaust, running the engine rich over a prolonged period of time will eventually plug/clog the converter, in which case you'll either need to hollow it out, eliminate it from the system all together, or replace it. Running rich will also wear out your spark plugs and O2 sensor much quicker than they ordinarily would, not that you'd be all that concerned about the O2 sensor if you were choosing to run lambda-less. If the piston rings are worn, running rich can also lead to a condition known as bore washing, whereby the access fuel will eventually begin to contaminate the engine lubricating oil, and thus necessitating more frequent changes of the engine oil.

Aside from all that, running rich will obviously decrease your fuel economy/efficiency experienced.

Thus, it's really up to you to decide what you want to do.

Complete failure of the frequency valve is somewhat rare. Usually, whacking it with a hammer is enough to un-stick it and get it working again.

While the valve could be your problem, it could also be the lambda ecu, O2 sensor, or the system relay.

When operating normally, you should be able to hear the frequency valve buzzing - if not, then you may not be getting power to it, in which case, you'd check the system relay.

First things first though - did you ever confirm proper operation of the vacuum systems on the CPR/WUR and electrical distributor? Personally, I'd start there before digging any deeper into the lambda system. Just because you're seeing a positive response when experimenting with the lambda system, it doesn't necessarily mean that you have a problem with the system.

After confirming proper vacuum systems operation, I'd check the relay that drives the lambda system - it's the fourth one from the left in the top row, or number 31 in the diagram below.

Best luck :thumbup:

http://i.imgur.com/4FvQG.jpg

[LoveThySpatula]

Frequency valve is a part of the lambda system, the purpose of which is to balance out the AFR so as to reduce emissions and provide maximum fuel efficiency. The frequency valve controls line pressure in the fuel distributor via instructions it receives from the lambda ecu, which operates in a fixed (open loop) or dynamic (closed loop) program mode. In closed loop operation, the ecu interprets signals it receives from the O2 (oxygen) sensor, which takes readings of the exhaust stream from its mounted location within the exhaust pipe.

The fact that you're idling and running fine without the frequency valve functioning at all suggests that your CO/AFR adjustment is set to run rich.

If you still have a catalytic converter as a part of your car's exhaust, running the engine rich over a prolonged period of time will eventually plug/clog the converter, in which case you'll either need to hollow it out, eliminate it from the system all together, or replace it. Running rich will also wear out your spark plugs and O2 sensor much quicker than they ordinarily would, not that you'd be all that concerned about the O2 sensor if you were choosing to run lambda-less. If the piston rings are worn, running rich can also lead to a condition known as bore washing, whereby the access fuel will eventually begin to contaminate the engine lubricating oil, and thus necessitating more frequent changes of the engine oil.

Aside from all that, running rich will obviously decrease your fuel economy/efficiency experienced.

Thus, it's really up to you to decide what you want to do.

Complete failure of the frequency valve is somewhat rare. Usually, whacking it with a hammer is enough to un-stick it and get it working again.

While the valve could be your problem, it could also be the lambda ecu, O2 sensor, or the system relay.

When operating normally, you should be able to hear the frequency valve buzzing - if not, then you may not be getting power to it, in which case, you'd check the system relay.

First things first though - did you ever confirm proper operation of the vacuum systems on the CPR/WUR and electrical distributor? Personally, I'd start there before digging any deeper into the lambda system. Just because you're seeing a positive response when experimenting with the lambda system, it doesn't necessarily mean that you have a problem with the system.

After confirming proper vacuum systems operation, I'd check the relay that drives the lambda system - it's the fourth one from the left in the top row, or number 31 in the diagram below.

Best luck :thumbup:

http://i.imgur.com/4FvQG.jpg


Thanks for the info. I think I just got excited when I got a response from the frequency valve being unplugged - this is a pesky bug in the system and a response after digging for a while was welcome. I have not properly tested the Control Pressure Regulator, I was actually on my way to do that when I messed with the frequency valve. On a side note, the CPR appears to have been replaced - it is definitely not factory, but it could have been 20 years ago for all I know. However, I will get to testing that when I get back to having some time.

I believe a previous post suggested I remove all of the vacuum lines from the CPR and see if anything changes?

Thanks again

[NightFlyer]

I believe a previous post suggested I remove all of the vacuum lines from the CPR and see if anything changes?

To definitively test the CPR/WUR requires a Bosch K-Jet inline pressure gauge, and then comparing the readings to those of normal operations as laid out in the workshop manual.

What I'm having you do is just confirming the proper operation of the two vacuum systems that intentionally affect how the engine runs.

Those systems work like this:

When you first start the engine cold, vacuum from the multi-port switch in the y-pipe (under the intake) is directed to the warm-up regulator / control pressure regulator (WUR/CPR). Once the running temperature reaches 104F, the multi-port switch redirects the vacuum to the solenoid hanging off the mixture unit behind the fuel distributor. When the engine is idling, the idle micro-switch is activated (closed) and instructs the solenoid to hold the vacuum there within the solenoid. When the the engine is under throttle, the idle micro-switch is disengaged (open) and causes the solenoid to actuate and release the vacuum being held there onward to the distributor in order to cause the vacuum advance of the timing.

Vacuum advance at the distributor should only be present when the running temperature of the engine is above 104F AND when the engine is under throttle. At all other times, there should be no vacuum advance at the distributor - NEVER when the engine running temp is below 104F (whether at idle or under throttle) and NEVER when the engine is at idle.

Test each system (CPR/WUR and electrical distributor advance) separately. To confirm operation, you simply pull the vacuum lines off the WUR/CPR and the electrical distributor's vacuum chamber and/or vacuum solenoid and check for the presence/absence of vacuum during the various stages of engine operation, making sure that it's present when you want it to be and not present when you don't want it to be.

Essentially, you're just making sure that the three port thermal switch is operating as it should, and that the distributor is being vacuum advanced only when it should be.

If both systems check out, we'll assume that pressure in the CPR/WUR is OK and move on and look at the lambda system, unless you have the Bosch K-jet pressure gauges handy, in which case, you'd want to confirm your pressures before moving on.

Personally, I think you're on the right track in suspecting the lambda system, but we'll walk though the steps just to make sure and avoid any unnecessary parts expenditures.

As both the CPR/WUR and lambda system affect fuel line pressure, it's very easy to mistake a true fault in one as being a fault in the other, which is why you have to diagnose these two things separately, but always in conjunction with one another (unless the symptoms are clearly indicating one over the other), if that makes sense.

Best luck :thumbup:

[LoveThySpatula]

Vacuum advance at the distributor should only be present when the running temperature of the engine is above 104F AND when the engine is under throttle. At all other times, there should be no vacuum advance at the distributor - NEVER when the engine running temp is below 104F (whether at idle or under throttle) and NEVER when the engine is at idle.

Test each system (CPR/WUR and electrical distributor advance) separately. To confirm operation, you simply pull the vacuum lines off the WUR/CPR and the electrical distributor's vacuum chamber and/or vacuum solenoid and check for the presence/absence of vacuum during the various stages of engine operation, making sure that it's present when you want it to be and not present when you don't want it to be.

Essentially, you're just making sure that the three port thermal switch is operating as it should, and that the distributor is being vacuum advanced only when it should be.


And it appears that the CPR / WUR are working properly. I had no vacuum at the distributor's vacuum chamber at start up, unless under load. However, vacuum was present after the engine got hot - which means the thermal switch is operating as it should.

So at this point, any suggestions of where to look next?

[NightFlyer]

And it appears that the CPR / WUR are working properly. I had no vacuum at the distributor's vacuum chamber at start up, unless under load. However, vacuum was present after the engine got hot - which means the thermal switch is operating as it should.

So at this point, any suggestions of where to look next?

When vacuum should be present at the CPR/WUR: only after a cold start up, and only for the first few minutes of running (until the engine coolant temp reaches 104F).

When vacuum should be present at the electrical distributor's solenoid: only when the engine coolant temp has reached 104F or higher.

When vacuum should be present at the electrical distributor's vacuum chamber: only when the engine temp has reached 104F or higher AND during open throttle events (both condition must be met - if only one is met, then there shouldn't be vacuum here). There should NEVER be vacuum here at idle ever (idle micro-switch engaged/closed).

Assuming that you tested everything correctly, and that everything is working properly, then we'll move on to the lambda system.

Based on what you've already described, you're going to want to check the lambda relay in the fuse/relay compartment. Swap it with a known fully functional/operational lambda relay, and then with the system fully hooked up (nothing unplugged) see what you get and if it's different. Note that the lambda relay is a special one and NOT interchangeable with the regular/typical relays. Do you hear the frequency valve buzzing at all? If not, then use a meter to see if there's power on the line at all. If there is, then try smacking the valve with a hammer to unstick it. If there isn't, then figure out why and remedy the electrical problem (this could be a lot of things, including corroded pins in the connectors, loose/backed-out pins in the connectors, something with the pins in the relay socket, bad RPM relay, bad ground, etc).

Report back once the condition of the frequency valve is known.

Best luck :thumbup:

[LoveThySpatula]

When vacuum should be present at the CPR/WUR: only after a cold start up, and only for the first few minutes of running (until the engine coolant temp reaches 104F).

When vacuum should be present at the electrical distributor's solenoid: only when the engine coolant temp has reached 104F or higher.

When vacuum should be present at the electrical distributor's vacuum chamber: only when the engine temp has reached 104F or higher AND during open throttle events (both condition must be met - if only one is met, then there shouldn't be vacuum here). There should NEVER be vacuum here at idle ever (idle micro-switch engaged/closed).

Despite having read your post at least eight times, I still misread it. I have no vacuum at the distributor advance when cold, but when hot, there is constant vacuum at the distributor advance chamber - at idle and under load. Was unable to confirm vacuum at the CPR / WUR at this time - I think the engine was already warmed up.

Side note: the frequency valve is buzzing away, I believe, as it should. Probably no need to mess with it as I believe my findings were coincidental.

[Bitsyncmaster]

there is constant vacuum at the distributor advance chamber - at idle and under load.

There should not be vacuum at idle. Most likely your solenoid connector has fallen off or the idle switch is not working (miss adjusted or broken).

[NightFlyer]

I have no vacuum at the distributor advance when cold, but when hot, there is constant vacuum at the distributor advance chamber - at idle and under load.

Well, then, that's not right, as there should only ever be vacuum at the distributor advance chamber when the engine is warm (104F+) AND during open throttle events (both conditions must be simultaneously present, otherwise there shouldn't be vacuum present at such location - and NEVER at idle), so let's tackle this problem first.

First, make sure that the idle micro-switch is in fact engaging (closing) at idle. If not, then you'll need to clean and lubricate the striker bracket arm (and possibly the throttle spool/cable/linkages, as may be required if there's something that's preventing the arm from freely fully pivoting), and adjust the striker screw as is necessary.

http://www.specialtauto.com/delorean-parts/images/idle-speed-adj.jpg

Next, use a multi-meter to test the idle micro-switch - resistance when engaged (closed) should be approaching 0 ohms, and when open should be approaching infinity ohms. If you get readings other than these, then the switch is bad and will need to be replaced.

If the idle micro-switch checks out OK, then you'll want to use your multi-meter to confirm power into the switch. If that checks out, then you'll want to turn your attention to the vacuum solenoid.

http://4.bp.blogspot.com/-Oi19y6MBgwU/UItvJ9aVCEI/AAAAAAAABh4/hTLqXBOCkhE/s1600/IMG_3910.JPG

Note that in the reference photo above, the power wire and vacuum hoses are not attached to the vacuum solenoid.

Again, use your multi-meter to confirm power at the solenoid when the idle micro-switch is engaged (closed). If you're not reading any power to the solenoid, then check the wire for a break/defect/short to ground/etc.

If power to the solenoid was always good when the idle micro-switch is engaged, then you know that you have a failed vacuum solenoid, and it will need to be replaced.

If any of that doesn't make sense or if you're not following with the way I've laid it out, don't be afraid to ask additional questions.

Best luck :thumbup:

[DMCMW Dave]

http://4.bp.blogspot.com/-Oi19y6MBgwU/UItvJ9aVCEI/AAAAAAAABh4/hTLqXBOCkhE/s1600/IMG_3910.JPG

:

Current events test. Why do you have rubber bullets all over your fuel distributor?

[NightFlyer]

Current events test. Why do you have rubber bullets all over your fuel distributor?

It's a picture from the web - not of my car :biggrin:

[David T]

It's a picture from the web - not of my car :biggrin:

Also be aware it matters which port the hoses go to. If you mix them up things won't work right. You should be able to hear the valve click when voltage is applied.

[Flash66]

Just to add. I hate the electrical connector that was used for this solenoid! I knock it off every time I have my hand back there. Thinking of soldering a better connector to the terminals mating a matching plug that snaps together.

[Bitsyncmaster]

Just to add. I hate the electrical connector that was used for this solenoid! I knock it off every time I have my hand back there. Thinking of soldering a better connector to the terminals mating a matching plug that snaps together.

+1
Been there, done that.

[NightFlyer]

Also be aware it matters which port the hoses go to. If you mix them up things won't work right.

I've not confirmed this myself, but I've read a few posts that imply/infer that some of the aftermarket vacuum solenoids on the market have the opposite hose arrangement vs the arrangement found on the stock/OEM vacuum solenoid.

So, yes, when ever trouble shooting the vacuum solenoid, confirm that the vacuum hoses are in fact properly connected to it.

[LoveThySpatula]

Well gents, sometimes is the simple things in life that drive you crazy.

After hearing you guys discuss the vacuum solenoid and hearing about how easily the connector falls off - something clicked in my rusty old brain. I believe it was NightFlyer (again) that posted that picture of the solenoid (and fuel distributor adorned with rubber bullets) saying that the hoses and the power were disconnected.

I took a look this morning and confirmed my suspicions.

The power wasn't hooked up to the solenoid. And I don't think is has been since I did the tune up.
Go figure.

I drove her around a bit today and she runs, I would say, 90% better... there is still that lack of acceleration at wide open throttle - not that I'm driving it like a punk kid in a civic - but trying to go up steep hills still results in having to back off the gas just a tad bit to keep accelerating... I'm going to take a risk and drive her to work today, I'll let you guys know what, if anything, happens.

EDIT: Also thanks for everyone's help in trying to figure this out, you guys have been a great help so far.

[NightFlyer]

Well gents, sometimes is the simple things in life that drive you crazy.

After hearing you guys discuss the vacuum solenoid and hearing about how easily the connector falls off - something clicked in my rusty old brain. I believe it was NightFlyer (again) that posted that picture of the solenoid (and fuel distributor adorned with rubber bullets) saying that the hoses and the power were disconnected.

I took a look this morning and confirmed my suspicions.

The power wasn't hooked up to the solenoid. And I don't think is has been since I did the tune up.
Go figure.

I drove her around a bit today and she runs, I would say, 90% better... there is still that lack of acceleration at wide open throttle - not that I'm driving it like a punk kid in a civic - but trying to go up steep hills still results in having to back off the gas just a tad bit to keep accelerating... I'm going to take a risk and drive her to work today, I'll let you guys know what, if anything, happens.

EDIT: Also thanks for everyone's help in trying to figure this out, you guys have been a great help so far.

Sounds promising so far :thumbup:

Yes, let us know how the drive today goes. And if possible, a video of any remaining issues would be great and could help us in narrowing it down for you.

[LoveThySpatula]

Well, after having another apparent breakthrough yesterday, she is still having issues. Went to start it up before work and she had the same problem, if not worse.

I have put together a video of the running issue - please be gentle, I have NEVER edited a video or posted one online. Let me know if this will point anyone in the right direction.

http://youtu.be/ReflDSH5Yc0

NOTE: I was not sure how to edit out half of the video so bear with me on that too, thanks.

[Flash66]

I'll bet you have the cleanest spark plug boots around! Honestly I'm thinking your fuel pump is on its way to the grave! A carbon copy of what mine did and a new fuel pump took care of it. Also one day it would run pretty good, and the next would run like crap like your video demo. 99.1% sure that this is your issue.

[Jonathan]

Well, after having another apparent breakthrough yesterday, she is still having issues. Went to start it up before work and she had the same problem, if not worse.

I have put together a video of the running issue - please be gentle, I have NEVER edited a video or posted one online. Let me know if this will point anyone in the right direction.

http://youtu.be/ReflDSH5Yc0

NOTE: I was not sure how to edit out half of the video so bear with me on that too, thanks.

Looking at your spray can usage and how things aren't improving, I'd start trying something else as that doesn't appear to be it.

To me it just looks like your car isn't being told to idle properly when there is no throttle being applied. I would bet on it being one or more of those components not electrically connected properly or for other reasons not getting the signals it needs.

So, check to see if your idle microswitch is working (and plugged in correctly as that white connector on the top of the intake on the left side has me wondering). Go over the electrical connections in that idle control system like the ones connected to the idle speed motor and the ones at the bulkhead connectors as well as behind the driver's seat on the ECU.

[Dracula]

At the behest of NightFlier, I have been asked to inform you that he was banned and therefore can't respond to inquiries any further unless you wish to come over to DMCToday.com

[LoveThySpatula]

I'll bet you have the cleanest spark plug boots around! Honestly I'm thinking your fuel pump is on its way to the grave! A carbon copy of what mine did and a new fuel pump took care of it. Also one day it would run pretty good, and the next would run like crap like your video demo. 99.1% sure that this is your issue.

Not the cleanest by choice, trust me. I've had a couple people tell me that the fuel pump is likely shot and I should just replace it now before it fails completely - I've been avoiding it mostly because of the price tag of the thing, but I may just have to bite the bullet and get it.


At the behest of NightFlier, I have been asked to inform you that he was banned and therefore can't respond to inquiries any further unless you wish to come over to DMCToday.com

Thanks for the heads up, do you happen to know his username over there? I could pop over if he has any advice - hate to bug the guy, he's been babysitting me for a week or two already.

[Ron]

$.02

The engine changes significantly when you spray the intake area by #2 and #3. This indicates a vacuum leak (intake 0-ring, or one of the lines in VOD...). The resulting lean mixture could explain the "backfire" while the engine is cold as well....

Edit: Same handle for NF

[Flash66]

Not the cleanest by choice, trust me. I've had a couple people tell me that the fuel pump is likely shot and I should just replace it now before it fails completely - I've been avoiding it mostly because of the price tag of the thing, but I may just have to bite the bullet and

If nothing else buy the old style on eBay for 125.00. I'm so confident 90% of your problem is fuel delivery. I've been EXACTLY where you are as seen in your video. Besides the apparent vacuum leak shown, your running super lean from starving fuel and there's your backlash from the intake. Your pump is shot.

[LoveThySpatula]

If nothing else buy the old style on eBay for 125.00. I'm so confident 90% of your problem is fuel delivery. I've been EXACTLY where you are as seen in your video. Besides the apparent vacuum leak shown, your running super lean from starving fuel and there's your backlash from the intake. Your pump is shot.

I've ordered a replacement pump (only the pump) to see if that fixes the problem. I tried running her a bit today and the issue was worse than it has ever been so I'm with you thinking the pump has decided to stop working.

I'll keep you guys updated.

Thanks again for all the help.

[LoveThySpatula]

Well put the new pump in and it runs worse than before, so I am at a bit of a loss. I did notice there is an inline check valve installed, and because the new pump has a check valve, I'll be removing the extra valve when I get the time (about two hours a week) to see if that helps.

With the new pump installed, I had to do the plug swap to even get it started - no biggie, I figured there was air in the lines. At first, it wouldn't run after swapping the plugs back. Finally started idling normal, but once again, no acceleration. Gave it gas and it died right away - worse than before. And it happened every time after I got it restarted as well.

Looks like I'm back to square one, any other ideas?
Maybe a trip to the repair shop?

[NightFlyer]

Well put the new pump in and it runs worse than before, so I am at a bit of a loss. I did notice there is an inline check valve installed, and because the new pump has a check valve, I'll be removing the extra valve when I get the time (about two hours a week) to see if that helps.

With the new pump installed, I had to do the plug swap to even get it started - no biggie, I figured there was air in the lines. At first, it wouldn't run after swapping the plugs back. Finally started idling normal, but once again, no acceleration. Gave it gas and it died right away - worse than before. And it happened every time after I got it restarted as well.

Looks like I'm back to square one, any other ideas?
Maybe a trip to the repair shop?

Should have flow rate tested the pump before going to the trouble of replacing it, but that's water under the bridge now.

What pump are you now running, and what inline check valve(s) do you have installed? Can you post a pic of your current fuel tank set-up?

Having an extra check valve in the feed line isn't going to cause the type of problem you're describing, thus don't bother uninstalling a nice inline one that you've already installed.

If you haven't done this yet, try unplugging the bulkhead connectors under the coil cover. Make sure that none of the pins in either the sockets or the plugs has backed out. Spray some electrical contact cleaner both in the sockets and in the plugs. If you notice any severe oxidation on any of the pins, clean it off as best you can. Reconnect everything and see what you get.

Best luck :thumbup:

[LoveThySpatula]

Should have flow rate tested the pump before going to the trouble of replacing it, but that's water under the bridge now.

What pump are you now running, and what inline check valve(s) do you have installed? Can you post a pic of your current fuel tank set-up?

Having an extra check valve in the feed line isn't going to cause the type of problem you're describing, thus don't bother uninstalling a nice inline one that you've already installed.

If you haven't done this yet, try unplugging the bulkhead connectors under the coil cover. Make sure that none of the pins in either the sockets or the plugs has backed out. Spray some electrical contact cleaner both in the sockets and in the plugs. If you notice any severe oxidation on any of the pins, clean it off as best you can. Reconnect everything and see what you get.

Best luck :thumbup:

Welcome back.

I'm running one of those $90 pumps off of SpecialTAuto and I'm running an SMC 410 5/16" check valve from US Plastics. I'll try to get you a picture of my setup tonight or tomorrow.

I just realized that I may have twisted up the pickup tube upon install of the new pump. I'll also check on that.

I'll also check on the bulkhead connectors tonight or tomorrow and report back.

[LoveThySpatula]

Welcome back.

I'm running one of those $90 pumps off of SpecialTAuto and I'm running an SMC 410 5/16" check valve from US Plastics. I'll try to get you a picture of my setup tonight or tomorrow.

I just realized that I may have twisted up the pickup tube upon install of the new pump. I'll also check on that.

I'll also check on the bulkhead connectors tonight or tomorrow and report back.

Pictures of the fuel pump setup.

http://i696.photobucket.com/albums/vv323/theblackgto/PART_1410373462229_0910141110_zpsfd7a0f52.jpg (http://s696.photobucket.com/user/theblackgto/media/PART_1410373462229_0910141110_zpsfd7a0f52.jpg.html )

http://i696.photobucket.com/albums/vv323/theblackgto/PART_1410374007988_0910141110a_zpsf8606b0a.jpg (http://s696.photobucket.com/user/theblackgto/media/PART_1410374007988_0910141110a_zpsf8606b0a.jpg.htm l)

Pickup tube was not twisted, just one of those things I forgot to check. Bulkhead connectors have very spotty, minimal corrosion. Something significant changed when I put the different pump in - I can't think of what it would be though. I don't suppose hooking up the power terminals backwards might cause this problem? I'm positive that I haven't, but I'm expecting that I'm missing something(s) obvious here.

[DMCMW Dave]

Pickup tube was not twisted, just one of those things I forgot to check. Bulkhead connectors have very spotty, minimal corrosion. Something significant changed when I put the different pump in - I can't think of what it would be though. I don't suppose hooking up the power terminals backwards might cause this problem? I'm positive that I haven't, but I'm expecting that I'm missing something(s) obvious here.

The pump will pump backwards. The car may actually run with the pump going backwards.

You will see +/- on top of the pump. + goes to the white/purple on the car side of the harness. Just out of your picture. I noticed you used generic spade connectors, typically when you do that you should make the connections opposite each other so you can't hook it up backwards.

[LoveThySpatula]

Well it wasn't plugged in backwards. I'm thinking of putting the old pump back in... At least it would be drivable on occasion with the old pump. Maybe the pump I got from Hervey is defective? It would be just my luck to get a faulty pump.