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so frustrated with this car



I took the ICM off and between the bottom and the metal plate its pretty corroid i dont know if that matters or not but im going down to autozone tomarrow and get it tested let ya guys know how i make out Thanks for all your help so far
 
Ok i took the ICM down to autozone and they hooked it up to a machine and they said it was good, so im stuck in tha same spot i was now, i dont know what else it could be? has anyone ever used that machine befor bc i asked the guy if i could go over and watch and he said no didnt seem like he hooked it up right is there another way to test?:th_angry2:
 
You said "theres spark coming from the coil both sides." If so, then your problem at cyl #3 isn't spark. Next thing you wanna do is see if the injector is getting pulse. If you're getting pulse and spark, then you most likely have a compression-ish issue or the injector is flaking out.

So lets make sure that you have spark and pulse.
 
A friend of mine has a 99 regal with the 3800 and he had the same problem, tried switching the injectors, had the ICM tested and replaced all plugs and wires, he ended up having to purchase a new computer for his car. As far as i know he hasnt had any other problems since, could be an option.
 


hmmm icm can b checked by advance auto. just go by with ur icm and they can test it. its under the coils. take coils off and unplug the harness going to it. should come off . sorry i meant duralast wires but ur prolly right bluegtp. had to re route the wires when tune up. but upon bringing wires back to autozone, they replaced it 100% and it still hesitiated. so i went with denso brand and not a problem. so... i donno to each is own.
 
1999GrandPrix said:
hmmm icm can b checked by advance auto. just go by with ur icm and they can test it. its under the coils. take coils off and unplug the harness going to it. should come off . sorry i meant duralast wires but ur prolly right bluegtp. had to re route the wires when tune up. but upon bringing wires back to autozone, they replaced it 100% and it still hesitiated. so i went with denso brand and not a problem. so... i donno to each is own.
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Two and a half hours earlier...


kawasakidrivinghick said:
Ok i took the ICM down to autozone and they hooked it up to a machine and they said it was good, so im stuck in tha same spot i was now, i dont know what else it could be? has anyone ever used that machine befor bc i asked the guy if i could go over and watch and he said no didnt seem like he hooked it up right is there another way to test?:th_angry2:
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Reading > You
 
its impossible to hook the icm up wrong...there is only one plug on the machines we use. you press start and tap the icm with a metal piece to simulate driving conditions. i always run the test 3 times to make sure. if it fails even one time i suggest replacing it
 
rocknnachos said:
You said "theres spark coming from the coil both sides." If so, then your problem at cyl #3 isn't spark. Next thing you wanna do is see if the injector is getting pulse. If you're getting pulse and spark, then you most likely have a compression-ish issue or the injector is flaking out.

So lets make sure that you have spark and pulse.
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Follow this guys lead. He knows what he's talking about.

The injector signal can be tested with a DVM set on "Duty Cycle". This is an easy way to measure pulse width. Take note of the stability of the signal. Get a reading from one of the other known good injectors and compare it to the reading from #3.

If the injector signal is good then the PCM is probably good. Move on to a compression test. If the compression test is good then I would probably replace the ICM or install it on one or your freind's cars and see if their car produces the P0303.
 
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well i switched plugs and wires swtched 3 and 5 had it scanned and it didnt change from cylinder 3 so i put a bottle of injector cleaner in it and a cup of mystery oil and cleared light. the light hasnt come back on yet! but the exhaust has a pretty big leak right after cat so maybe the leak is causeing a little ruff idle.
 


In my experience compression tests don't tell you the whole story. Heck, most of the time they are done wrong and they tell a bad story about something that is fine. If you smell gas in the oil, do a compression test. If you smell gas in the exhaust, check injectors.
 
I had a mechanic do compression Test and he said #3 cylinder had 60 PSI and the other ones had 170 so he told me i would have to take the head off and have it looked at. the car runs fine driving and it went almost 20 miles and the check engine light didnt flash or come on, then idling it came on, anyone else have a idea for me or am i screwed thanks
 
If you say it runs fine driving and then idles like crap I have no idea how it could have a compression problem. If your still getting misfire codes I still think its ignition problem.
 


98GrandPrixIraqVet said:
toast a valve or something geezus christ people dont you read the thread !? it runs fine except at idle!
Cmon this cant be that hard I still say its ICM or at the very least ignition system related its throwing a misfire code lol why would the code lie to you!
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I did read the entire thread and that's why I suggested that there may be a problem with compression.
 
kawasakidrivinghick said:
I had a mechanic do compression Test and he said #3 cylinder had 60 PSI and the other ones had 170 so he told me i would have to take the head off and have it looked at. the car runs fine driving and it went almost 20 miles and the check engine light didnt flash or come on, then idling it came on, anyone else have a idea for me or am i screwed thanks
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You may have ball-peened a seat. Do you have the ability to remove the head yourself? It's easy, especially with our remedial valve train. Just make sure all parts go back on in the same place. If it is the head I would just go and get one from a yard. They're dirt cheap. The other option would be to have a machine shop do the work for you. That's if it's salvagable.
 
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