**NOT RESOLVED**Randomly losing cylinders/dying**NOT RESOLVED**

[prove_it]

Sounds like you made some head way. Good job. 20 year old connectors are definitely an issue. Hope that's all it is.

 

[5OF2k]

Quoting Racah15:
Hey man don't be afraid to ask for help locally. Give me a holler if you need any help. I may not know too much but 2 people checking it out is sometimes better than 1. I have a laptop and ignitors, CAS, and other goodies. I even have a 90' we can try (has it's own pigtail)



Appreciate the offer Abe, and thanks for the coils as well!

I did get a laptop to use for the day, unfortunately I work all day instead of being able to plug away on Johnny like I want to.

I'll be soldering the new pigtail on this afternoon and then I'll be downloading the AEM software on the computer so I can connect and get my log on/doublecheck the tables and such. If you're interested in giving me a hand, that'd be cool man. I do plan on buying a 12er and diving in! lol

-Jake

 

[5OF2k]

So!

I found a couple known good ICM's, and replaced the old(less than a year old, actually) unit. I didnt have a VOM handy so I was unable to test the old unti pre-replacement, so it being fixed could be nothing more than a coincidence.

Anywh, replaced the ICM and started it up, ran fine. Im under the hood wiggling and jerking and so-on and come accross the CAS plug(again)and give the wires some movement and it dies. So I go to try and re-start, and it wont. Head back out under the hood and pull the wire shrouding back and see under the shrouding a bunch of breaks in the wire insulation, and a couple spots where it had been making contact. THIS explains the intermittency of the whole issue.

Anywho, wound up pulling ALL of the shrouding off of the CAS section of the harness and finding MULTIPLE breaks. So, I repaired them all (6-8 breaks in the insulation) with heat-shrink, replaced the CAS plug/pigtail with a newer NT unit(not nearly as brittle), and it's been fine since.

Now, Being as the spark was dying out, Im pretty sure the ICM was also bad, but I beleive the main culprit of the issue was due to the CAS wiring.

I'v enow driven about 70 miles ranging from mid/light-throttle cruise to WOT "angry at something" beat-your-mother driving, without issue. I also finally bought my own mini laptop for logging/tuning purposes, and everything looks really good with it still, which is always good!

Thanks again for all of the help, gentlemen. Issues like THIS goes to show sometimes you have to think outsisde of the box, AND under the shrouding.... /ubbthreads/images/graemlins/laugh.gif

-Jake

 

[prove_it]

That's the fun with electrical faults. Gotta love them. Glad you found the problem and are back to "angry at something" beat-your-mother driving. /ubbthreads/images/graemlins/grin.gif

 

[EHmotorsports]

great to hear you were able to resolve the issue happy hunting

 

[5OF2k]

Well, isn't it a fantastic world??

....so, this morning Im going to leave my GFs house on the way to my house to get ready for work. Out of nowhere at a stop sign, BOOM, car dies. I think, oh great.

Try to start it again, and it fires but not without giving it full throttle and only running on a couple cylinders.....

Now, the guy I got the ICM/TR units from said he was "pretty sure" they were good, so he gave me two, simply because he was unsure which one was 100% good. Luckily, I had the other one in the car and it was simply a matter of plugging it into the harness.

Anywho, plug the new one in, BAM, fires just fine, no worries. So I drive on to my house.

Now, being as it is a nicer day, I decided to take the bike to work rather than my car. I get back to my house, gather some parts im selling, and get ready to leave. On my way to my parents house, sitting at a light (middle of Friday traffic) and BOOM, car dies.

Go to re-start, and same thing, running like complete and utter poop.

So, I manage to get it home and hook it up to the laptop for a logging session. Now, I havent really looked into it too much other than while I was driving(I know, I know lol) and slightly before coming here for an update, but it looks like the IDC and pulse rate shoots through the roof. In real-time it looked like the PR was around 1k when the car was running normal, and then would jump up tp above 10k when it was acting up.(will attach a couple logs; one good and one bad)

Now, this verifies what I already know: Im getting too much fuel. The question is: WHY.

Now, also in the logs you'll notice the AFR readout is single digit. It's been like that since day 1, and its due to the redout being funky, not so much the actual AFR(I dont believe). I've been meaning to go in and update the furl type/redout for the sensor display, but never get around to it.... I'll do that here in a bit, actually.

So, andyway, any ideas?? Im getting sick of this, and have a feeling it's something rediculously obvious, that Im just COMPLETELY missing!

Thanks in advance!

-Jake

 

[5OF2k]

Dammit, how do I attach a log??

 

[strokin4dr]

Check the ECT wires under the hood. They get very brittle and will cause the car to run super rich if broken. You may just have a partially broken wire giving you intermittent issues. I traced a no start/barely run condition to a broken sensor ground wire for the ECT on the car I picked up last year.
There are 2 wires running to the sensor, check both. They are pins 20 and 24 at the ecu. Use an ohmmeter from the end of the wire at the sensor to the other end at the ecu. Good luck.

 

[5OF2k]

CheckeD those yesterday actually, and theyre good. Its also running GM style ECT sensors due to the AEM, and has a seperate harness for that and the fan circuit. I know that sounds weird and Im prob not explaining it the best way, so I'll try to take some pics and stuff later so you can see what Im talking about.

Received a another known good CAS last night from Racah15(good good guy, helped me out more than I can say, and more than once) Im gonna throw in here in a little bit and log some more. We'll see how it goes!

Appreciate the replies!

-Jake

 

[5OF2k]

ok, let's not all talk at once, deal?? /ubbthreads/images/graemlins/smile.gif

So, I've tried a few things, all fuel/ignition related without success. So far, I've repaired CAS wiring and added a fresh new pigtail, tried 2 known good CAS, 3 known good ICM/TR units, 2 known good MAP sensors, and 2 sets of known good coils. The issue comes and goes as it pleases, and I am literally about at my wits' end.

Anyway, here are the footnotes:

Car is at idle, idling beautifully normal. I'm seeing IDC of 0.0000 and pulse rate of 38-40mu(microseconds). Out of nowhere, IDC jumps to 58-60% and pulsrate up to between 10k-14k mu. ZERO change in throttle %, RPM(other than dying because of all of the fuel). Just BOOM, done. As though Im suddenly going into full boost and WOT, only im at idle, sitting still....?

So again, I ask WTF!?!?! ANY other ideas??

Thanks in advance, I REALLY appreciate it!

-Jake

 

Might sound strange but, does this happen when are low on fuel i.e 1/4 of a tank?
you could try and ask to borrow a ECU...

 

[5OF2k]

That doesnt appear to have any affect on anything, that I've noticed anyway. IIRC, it'll do it regardless of fuel level.

I would love to borrow an ECU, the only issue is it's next to impossible to find an AEM V1 30-1300 ECU that isnt being used by someone already.... Just my luck!

-Jake

 

[gvr4ever]

I was going to post because it sounds like everything was electrical, but you are having the same problem I did. A compression test gave good results, but I was getting a random cylinder failure. After checking/replacing everything fuel/timing/spark related, I really had no other choice but to take the head off.

Found coolant in cyl 1, but the leak was so small that the problem came and went. Very hard to figure out. The deck was so barely warped that when the engine was hot, it would actually seal enough to run okay for awhile.

I don't know if you are having that problem or not, but if you've checked everything on the fuel/timing/spark side and its still not working, you might have to go digging.

 

[cheekychimp]

Jake,

You must be going mad dude. Stick with it, like you said hopefully it will prove to be something simple. We'll get there eventually.

You said this issue seems to come and go as it pleases, but reading through this thread it seems to happen fairly consistently when coming to a stop/sat at a stop light. I cannot explain your logs other than the obvious that you are getting too much fuel. That said, could it in any way be affected by either the TPS or the Throttle closed switch? I am wondering if the ECU could (somehow) be getting tricked into thinking your foot is on the gas, therefore adding fuel whilst the throttle plate is still closed leaving you running pig rich. I cannot for the life of me figure out how or why that would happen but something is screaming out to me that this has something to do with the TPS i.e. the car thinking it is at part/full throttle when it should be at idle.

Paul.

 

[5OF2k]

Quoting gvr4ever:
I was going to post because it sounds like everything was electrical, but you are having the same problem I did. A compression test gave good results, but I was getting a random cylinder failure. After checking/replacing everything fuel/timing/spark related, I really had no other choice but to take the head off.

Found coolant in cyl 1, but the leak was so small that the problem came and went. Very hard to figure out. The deck was so barely warped that when the engine was hot, it would actually seal enough to run okay for awhile.

I don't know if you are having that problem or not, but if you've checked everything on the fuel/timing/spark side and its still not working, you might have to go digging.



I hear you there, but this definitely isnt losing cylinders due to anything other than excessive fuel. It's literally DUMPING fuel in at double or triple the rate it should at idle, and if I keep it running and it keeps happening, it'll foul the plugs in a few minutes/cycles. Its really staggering, honestly.

Quoting cheekychimp:
Jake,

You must be going mad dude. Stick with it, like you said hopefully it will prove to be something simple. We'll get there eventually.

You said this issue seems to come and go as it pleases, but reading through this thread it seems to happen fairly consistently when coming to a stop/sat at a stop light. I cannot explain your logs other than the obvious that you are getting too much fuel. That said, could it in any way be affected by either the TPS or the Throttle closed switch? I am wondering if the ECU could (somehow) be getting tricked into thinking your foot is on the gas, therefore adding fuel whilst the throttle plate is still closed leaving you running pig rich. I cannot for the life of me figure out how or why that would happen but something is screaming out to me that this has something to do with the TPS i.e. the car thinking it is at part/full throttle when it should be at idle.

Paul.



I kind of thought that as well, but the only time Im seeing anything with the throttle change is when the car is dying due to the fuel being dumped in. I can see in the logs the fuel suddenly DUMP in, and then I have to floor it to get it to burn off the fuel... Im definitely going mad though, FOR SURE!!

the last couple days have been BITTER cold, but its supposed to be nicer the next couple of days. Im planning to get the DVOM out and ohm some connections, and test the voltage to the sensors. With any luck it'll help me figure out if everything is working properly....

Im also going to be calling AEM directly, to talk to them about the 30-1300 box and see if the issue Im having is common or possibly(the worst case) the ECU itself, or if theyre tech dept would be able to point me in the right direction or something.....?

We'll see!

Appreciate the replies and ideas fellas. Sorry if it sounds like Im shooting down your suggestions or something like that, I've just ran through about every damn scenario I could fathom in my head already. It's making me CRAZY!!

-Jake

 

[gvr4ever]

How can you tell if it's dumping fuel or just not getting combustion? I had the random rich random Subaru sounding problem too.

If it stays the same, then it could be something else. If it gets worse, its very likely the head gasket.

Next easier/cheaper step might be to send your injectors off to get tested. They can actually fail and pump too much fuel.

 

[5OF2k]

Not to be a rude ass, but did you read the rest of the thread?

I said earlier a few times Im seeing my IDC and pulse rate randomly shoot through the roof, and that Ive already swapped a number of different parts for other known good parts, injectors included.

For instance, normal IDC is 0.00000% at idle, suddenly it'll shoot up to 40-50%. At the same time, my normal pulserate is around 1800mu(microseconds) and it'll out of the blue jump up to 14k+mu. That along with my plugs becoming fouled and literally dripping with fuel are what tells me its dumping fuel in.

Like I said, Im really not trying to be an ass here, and i really do appreciate the feedback but this is all stuff thats been covered already in this thread. /ubbthreads/images/graemlins/frown.gif

 

[gvr4ever]

I read the thread, but I missed that you changed injectors. If you are missing compression, the ECU can't compensate fuel delivery. I had the same problem and yes you are being a ass.
Go at it alone. I'll stop giving input.

This forum is going down hill.

 

[5OF2k]

Quoting gvr4ever:
I read the thread, but I missed that you changed injectors. If you are missing compression, the ECU can't compensate fuel delivery. I had the same problem and yes you are being a ass.

Go at it alone. I'll stop giving input.

This forum is going down hill.



Chillax dude, Im sure you'd see it as a bit annoying if you had an issue and kept getting recommended things you've tried before. I appreciate your input though, really.

As far as the compression thing goes, I tend to think if that were the case it'd be constant rather than intermittent. After all, an engine is really nothing more than a mechanical, self sustaining air pump. If compression were low, I could see your point, sure, but it would be constant. You dont see compression numbers coming and going like that. When its' bad, its bad.

-Jake

 

[EHmotorsports]

something obviously is causing the injectors to go crazy. so you have at least three things to check. 1 Component, 2 signal, 3 control.
this is the three basic steps in diagnosing a car. is the signal to the ecu getting a false reading? if not is the component causing the issue? or is control causing this? what is log able with AEM's unit? if its anything like other stand alone computers you can log all signals coming in. what do they tell you? is temp,rpm,O2 not correlating with what is actually going on? yes injectors are going crazy with high duty cycles but what signal is the computer seeing that is causing this?