3rd brand new OEM ac delco icm failed after five minutes. Tested pick up coil, ignition coil and everything seems to be fine. Code 42 is showing on OBD1. Engine starts and runs on 0deg but does not advance timming on higher rpm. What could be the possible cause of repeated icm failure in such short time?
Thanks in advance

 

1. WHAT VEHICLE???

2. HOW do you know the ECMs are "failing"?

3. HOW does the engine run different "after" the ECM fails?

4. Have you followed the real, live diagnostic procedure in the service manual for Code 42?

 

ICM, not ECM. Car is Camaro 5.0 tbi
It stahls, starts backfiring from TBI when i pedal it. It dosent change ignition timing. I follow procedure and it turns out that is ICM faulty. PS i did also try some cheap replacement and it also fails in 5 minutes but that one has stop giving impulses to coil and there was no spark.

 

First thing I think of when there's repeat ignition module failures, is a defective ignition coil.

 

And how could i test it out to see? I cant get hands easy on parts because in Croatia i dont have parts store for American cars and i need to wait every part about 4-6 weeks.

Tnx

 

You must use a heat transfer paste between the ICM and the plate in the distributor it mounts to. ( The heat sink compound for computer CPU's works very well ) Also only use AC Delco or Delphi ones as the aftermarket ones don't last. Attached is the troubleshooting chart to diagnose the problem

 

 

 

I would suggest changing the coil. Just because it sparks and passes the ohm spec does not mean the internal insulation has not broken down and it is not arcing internally.

 

I think we found problem. It is dashboard, connections are bad and someone has frankensteined the board. Now i just need to see if the ICM is bad, and if it is that was the reason.