I've never came across this problem before. Did a bunch of searching, did some trouble shooting but still not getting the results/answers i'm looking for.

Recently my car started hesitating while driving, like major power loss. Almost to the point of stalling. Best way to describe it, is the feeling of running out of gas(I had a full tank). I pulled over, still running the engine kept hesitating and wanting to die but didnt. I shut the car off, turned it back on and it ran fine. I though it to be odd and ignored it. About a week later it happened again. I checked all plugs, fuses, connectors, etc to make sure they were snug/tight but everything checked out ok and didnt make the problem go away. Now i cant drive more than a mile or two before it starts to spit and sputter and out right die. Sometime i try to restart the engine and it just turns over but never fires, or it will fire but wont start, or it will start but barley idle(300-600rpms) and backfire every 3-5 seconds. I got it in the garage, checked the fuel filter(it was fine), fuel pump pumps plenty of fuel, took out the Camshaft sensor cleaned it off and put it back in, checked the MAP sensor and cleaned it, cleaned the TPS and checked the injectors. All seemed ok and in working condition. I started the car, (fired right up) and idles fine but you can still hear a pinging/popping sound coming from the Catalyctic Convt area of the exhaust. I figured it has to be the Knock sensor, TPS, or Camshaft sensor causing the detonation/bad timing. So i tried process of elimination by unplugging each one of the sensors one at a time. But unplugging them made absolutely no difference in performance. So Im out of Ideas as to what could be bad. Im open to any and all suggestions or ideas.

Thanks

By "checked" you mean tested right? My MAP sensor had a random glitch one day and the car kept stalling like it was out of gas. It did this intermittently a time or two within 20 minutes and hasnt had a problem since. It did, however, throw a CEL. I cleared the check engine light and it's continued to run fine ever since. Never had my TPS go out, so I wouldn't know the symptoms of that. usually it's just a rough idle... I have had my crank sensor go bad and the car ran like dog ass as well, but I see you have a 95, i don't think they used crank sensors did they?

Since rereading your post, your symptoms are almost exactly like my MAP sensor glitch... I would try replacing that first off... Like I said, I have the original MAP sensor, and it just glitched one day. Just because it's reading OK may not mean its ok.

It sounds like you ignition control module is going bad.

I bet you got a faulty coil cover.

Quote:

I bet you got a faulty coil cover./quote]

do you mean coil pack? Cuz i dont really see how the housing could go bad.


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93 Supra TT
98 Audi A4
95 Cavalier Z24

The housings go bad all the time...

OK, so today i was tinkering around under the hood, Changed my oil and unplugged all the clips from the sensors and cleaned them with contact cleaner to make sure all the clips/sensors were making a good connection. I changed the plugs as well. I fired the car back up and everything seemed ok. I revved it up a few times, no hesitation, detonation, etc. I unplugged the MAP sensor and got the typical symtoms, bogged down and then resumed normal idle. Gave it gas and it spit and sputterd and barely wanted to rev up. Reconnected MAP and everything back to normal. So i decided to take it around the block. Did a lap around the block without any problems so i got on the main road and made a full throttle run starting in second gear (auto), smooth power up until redline...... and thats where it stayed, bouncing off the rev limiter. It wouldnt shift into 3rd. I let off the gas and then it started to spit, sputter, and ultimately died. Turned the ignition off and attempted to restart. It cranked a few times and fired right up. Hesitated a little bit but went back to normal idle. I eased it back to the house and thats where she sits.

A bad MAP sensor wouldnt effect my shift point near redline would it? The hesitation and ruff idle makes sense but not shifting???

A bad ignition control module makes more sense if its getting/sending a bad signal from/to the ECU, would it mess with your shift point??

Im tight on money and cant afford to fix everything that it could be. I just want to fix what IS wrong. LOL Im sure you all know how i feel. Thanks for all your input so far.



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93 Supra TT
98 Audi A4
95 Cavalier Z24

IIRC, I remember my car doing something wierd when it comes to shifting when my map sensor had a glitch, because I was scared to try to drive it home.. MAP sensors are cheap... like $27. Just try it. If it doesnt fix the problem, just return it. =P

Sounds like a good idea. Ill try that tomorrow and see if that solves my problem.


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93 Supra TT
98 Audi A4
95 Cavalier Z24

Also, take your icm with you and have it tested at autozone (yes they can test it) just to be safe...

My next guess would be test the tps with a multimeter...

does your CEL light flash? if so its your coil pack causing the misfire, and you need to replace it. mine did the same thing.

I had a coil blow and the cel came on and the car was running on 2 cylinders and would barely move. When my coil housing was shot, cel never showed its ugly face.

My CEL is on, but the only code its throwing is from my O2 sensor. Im gonna swing by Autozone today and have them check out my ICM. I'll keep you guys posted.


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93 Supra TT
98 Audi A4
95 Cavalier Z24

OK, so my ICM tested good. I bought a new MAP sensor and still same issue. So out of curiosity i started screwing around testing out different things. I have it narrowed down to a few things. Bad Plug Boots, Coil or Coil Cover. How did i narrow it down? Well it was kinda by accident. After i cleaned up the spark plugs, boots, little springs inside the boots, springs inside the Coil cover and the coils themselves i put it all back together. Knowing i would probably have to take off the IDI cover again, I didnt tighten it down with the 4 bolts. I just set it snuggly on the engine. I fired up the car and it ran smooth for a while. Revved it a few times and it started to spit and sputter and back fire a few times. I set my hand in the IDI cover to balance myself while i gave the throttle a push and it revved and sounded fine. As soon as i took my hand off the cover it immediately started to spit, pop, bang, etc. While giving it some throttle i reapplied pressure to the cover and symptoms went away, released pressure and you guessed it. So i guess im getting a bad connection somehow from my coils to the plugs thus creating my problem. I have new plug boots on the way. if that doesnt solve my problem, im getting rid of the crap ignition system altogether and going with MSD Coils and a good set of wires.


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93 Supra TT
98 Audi A4
95 Cavalier Z24

Bringing the thread back.... Ok, So I've replaced the spark plug boots, replaced the MAP sensor, gave all the connecting metal parts a dab of contact grease, tested the ICM (autozone) but my car is still acting up. I drove the for the first time since December. I let the car idle till it was up to operating temp and then i took it for a spin. I drove it easy for about 10 min with no issues. I decided i would get on it. I gave it full throttle in second up to redline, once it got there it just bounce off the rev limiter(auto) until i let off. Once i let off it spit sputtered and backfired so badly that i seen the street light up behind me the fireball was so large. I shut the car off, restarted it right away and it ran fine. But after that it started to do the same thing if i would give it anymore than 50% throttle or would get just about to redline (5-6K) and then do it.
The only other thing that i for sure 100% know is wrong with my car is i have a bad O2 sensor. But im not gonna replace that until my car is fixed cuz with all that fuel being dumped into my exhaust will prolly just ruin it anyway. I'm gonna try to pick up a new coil pack housing this week and try that. Does anyone have any other suggestions of things to look at?


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93 Supra TT
98 Audi A4
95 Cavalier Z24

check the coil pack housing. Makes sure the springs are not burnt up or burt up under the springs. The springs are located on the inside of the cover. I had a similar problems.

Not the Housing, I bought a brand new one from autozone and threw it on. It came with new springs and those little green insulators. I swapped everything out and gave it a run. Same Issues. Waste of $47 if you ask me. It gets just before redline and spits, sputters and as soon as i let off the gas it looses all power and eventually dies. Occasionally, i can just turn off the key and restart it and it'll be fine. But most of the time it wont restart, just keeps turning over and wont fire. sometimes one or two of the cylinders fire but it wont start. Im out of ideas unless its my ICM. The only thing i can think of is its the ICM. even tho i had it tested, the ICM wasnt under a great deal of load when tested. And my problems only seem to start when i give it full throttle near redline. Then it seems like after that it will do it at any rpm. So im clueless as to what it could be.


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93 Supra TT
98 Audi A4
95 Cavalier Z24

Definately not the O2 sensor either, I just replaced that. No change in symptoms


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93 Supra TT
98 Audi A4
95 Cavalier Z24

Im actually starting to wonder if your Catalytic convertor is actually clogged up. Only causing issues after its heated up. Also, the O2 you installed, was it a Bosch?? If so pull that out, and get a new one (Bosch's do NOT work with our cars for some reason). Is your CEL still on?? if so whats the code?? Also, have you checked for simple vacuum leaks?? If not, go and get some carb cleaner, and spray the throttle body down (your gonna need to remove the plastic housing going onto the throttle body) and the injectors. I had a stupid issue with my girls old vert and found out the injectors were leaking way too much air into the cylinders, changed the o-rings on them yanked out the Bosch O2 and fixed the issue. The problem I had too was random sputtering, and stall outs. Try that and get back to us.

LOL, definately not a clogged catalytic convertor, mine is punched through. As for the CEL, the only code it throws is for the O2 sensor, and no its not a Bosch. Im gonna disconnect the battery and let it sit till i get off of work tomorrow to reset the code for the O2 sensor and see if it comes back. Throttle body is clean, i cleaned that not too long ago. I didnt think about the o-rings on the injectors. That doesnt quite make sense tho. High RPMs = more vaccum; more air and the same amount of fuel would create a leaner A/F mixture. But when my car back fires it throws quite the big flame out the back. And when I mean big, I mean it lights up a dark street that already has street lights. Something you would see come from 700+hp car running way to rich. I have a feeling its still my ICM. So im gonna pick one up after work tomorrow and see what that does.

Things I'm going to check:
ICM....$140
O-rings....$3
anything else you guys can think of....Priceless


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93 Supra TT
98 Audi A4
95 Cavalier Z24

well, altho you make sense, my girls car was running righ as hell, and it was bad orings on the injectors. Just grab the can of carb cleaner and spray the lines down, it never hurts to try. It could very well, be your ICM also. Never hurts to check everything. Goodluck!

Aaaa Haaaa, at last I have solved the problem with a little help from my j-body friends...

I did replace all 8 of the injector o-rings which wasnt the issue, but that car did seem to idle and run a tad bit smoother. Could be cuz i cleaned the injector tips as well?

But it was my ICM after all. I put in a brand new one today and all my symptoms went away. I drove around for about a half an hour and did several 2nd gear pulls and it purred all the way to redline and shifted into third just like it should everytime. Idles great too.

My CEL is still on, code P0134. But im hoping that will clear itself up in a few start ups as i just replaced the O2 sensor and the vaccum line that goes from the FPR to the intake manifold yesterday.

Just wanted to say THANKS for everyones help and input. You should all be glad to know there is 1 more J-body back on the road


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93 Supra TT
98 Audi A4
95 Cavalier Z24

ok So i thought the ICM was the only problem. But as i know now that was not the case. It was part of the problem, but not the entire problem. So after I installed the BRAND NEW ICM, my car ran great great for 2 days. I picked up a USED ICM locally and put that in so i could take back the NEW ICM and get my $140 back. So when I swapped in the USED ICM inplace of the NEW one, I also took out the NEW coil housing and put in my old one. As the New one didnt make any improvements when i had the BAD or NEW ICM in it. SO i figured i would get my $50 back from that. So currently the only thing I changed from the Start of this whole escapade is a GOOD/USED ICM and new spark plug boots.

My car is still randomly hesitating, mis firing and what have you. I had to run a few errands so i figured i would drive the cavy. I never revved it over 4K and prolly didnt give it anymore than 50% throttle when i was driving it around when it started acting up again. Doesnt seem to back fire nearly as much (only did it once so far) and when it is mis firing while doing a second gear pull, it DOES shift into third just fine. So my shifting issue was clearly caused by my BAD ICM. So im thinking maybe i have bad coils? I already ordered some new ones and should be here in a few days. But im just confused cuz its so random. It does it when it wants and stops when it wants. If it was the coils, wouldnt it misfire consistanly? Is there something else electrical that maybe i should be looking at? Possibly the ECU?


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93 Supra TT
98 Audi A4
95 Cavalier Z24