04 Cavalier Ecotec 2.2 DOHC ICM questions

[buckz6319]

Hi
I'm working on a 2004 Cavalier Ecotec 2.2 DOHC automatic with 116,000 on the clock. This car belongs to a close friends daughter. I have done major work to it for them several times in the past. I now have it back with another issue, and hope to get some input and thoughts on what maybe the issue.

I feel like maybe it's the ICM which I believe incorporates a crank, and cam position sensor of some sort, all in one unit.

Symptoms
1. Engine will suddenly quit without warning, DTC P0300 . Engine runs rough sometimes, and smooth most of the time. The car can be driven and has power.

2. The fuel pump relay makes a noise when this happens, and I think because of the computer takes over the fuel pump control, after engine is running?

3. The engine starts up after it dies, only by turning the ignition key back to the off position, then back the the on/crank position.
but I will attempt to start if I try to restart from the key on position, but has a hard time doing so.

Test Drive
I knew the fuel pressure regulator was bad, actually it was leaking from the outside of the housing, so I replaced it asap, fire hazard , and I thought maybe the diaphragm was leaking inside also, possibly causing this issue...

I drove it about 28 miles without issue, at speeds from o-70MPH. I had highway, and city driving during this test drive, but during 3 of my last stops before I got her home she quit without warning. I was able to get it restarted, but only after KOKO.

Now I'm no professional tech, and hope I described this issue well enough to get some input, on possible causes. I have done hours of searching, which is what I do every time I work on something different , and this ignition is different.

I would like to know how to troubleshoot the ICM if that is causing the issue, if not which way should I proceed?

I have checked the fuel pressure, when first energized KOEO ( 57psi) and when engine running ( 54psi ). I tested the fuel pump volume at 1Qt for 40 seconds, but I could only do this while engine is running, can't find anything on bypass the computer to run the pump, without the engine running....I'm not ruling out the pump yet but at this point I'm moving on to other areas.

I have cleaned out the IAC and It's working properly at the moment.

The engine has excellent vacuum 19-20 steady

spark plugs look a little lean, but there not but just a few weeks old.

The injectors are receiving a command to open on each one, however I can't check the spray pattern, nor if they are clogged, but I did clean them a few months ago, after head and timing chain replacement.

I have spent a lot of time trying to find the cause of this issue, but don't have the sophisticated equipment that professional shops have, but I love to wrench it! and help out close family and friends.

any help would be greatly apprecated!!! and will help me help someone else

thank you

[j cAT]

Originally Posted by buckz6319

Hi
I'm working on a 2004 Cavalier Ecotec 2.2 DOHC automatic with 116,000 on the clock. This car belongs to a close friends daughter. I have done major work to it for them several times in the past. I now have it back with another issue, and hope to get some input and thoughts on what maybe the issue.

I feel like maybe it's the ICM which I believe incorporates a crank, and cam position sensor of some sort, all in one unit.

Symptoms
1. Engine will suddenly quit without warning, DTC P0300 . Engine runs rough sometimes, and smooth most of the time. The car can be driven and has power.

2. The fuel pump relay makes a noise when this happens, and I think because of the computer takes over the fuel pump control, after engine is running?

3. The engine starts up after it dies, only by turning the ignition key back to the off position, then back the the on/crank position.
but I will attempt to start if I try to restart from the key on position, but has a hard time doing so.

Test Drive
I knew the fuel pressure regulator was bad, actually it was leaking from the outside of the housing, so I replaced it asap, fire hazard , and I thought maybe the diaphragm was leaking inside also, possibly causing this issue...

I drove it about 28 miles without issue, at speeds from o-70MPH. I had highway, and city driving during this test drive, but during 3 of my last stops before I got her home she quit without warning. I was able to get it restarted, but only after KOKO.

Now I'm no professional tech, and hope I described this issue well enough to get some input, on possible causes. I have done hours of searching, which is what I do every time I work on something different , and this ignition is different.

I would like to know how to troubleshoot the ICM if that is causing the issue, if not which way should I proceed?

I have checked the fuel pressure, when first energized KOEO ( 57psi) and when engine running ( 54psi ). I tested the fuel pump volume at 1Qt for 30 seconds, but I could only do this while engine is running, can't find anything on bypass the computer to run the pump, without the engine running....I'm not ruling out the pump yet but at this point I'm moving on to other areas.

I have cleaned out the IAC and It's working properly at the moment.

The engine has excellent vacuum 19-20 steady

spark plugs look a little lean, but there not but just a few weeks old.

The injectors are receiving a command to open on each one, however I can't check the spray pattern, nor if they are clogged, but I did clean them a few months ago, after head and timing chain replacement.

I have spent a lot of time trying to find the cause of this issue, but don't have the sophisticated equipment that professional shops have, but I love to wrench it! and help out close family and friends.

any help would be greatly apprecated!!! and will help me help someone else

thank you

stalling random is a tough one. the little I know about this engine many have had ECT issues. the connector / sensor .. then stalling.

[buckz6319]

Originally Posted by j cAT

stalling random is a tough one. the little I know about this engine many have had ECT issues. the connector / sensor .. then stalling.

thanks for your input. I appreciate it!
I will continue to troubleshoot