Car left me stranded New Years Eve with a no spark condition.

Now, the problem seems to be intermittent. I have the pulse coming to the ICM(I have a spare opti I turn real slow to test this) and 12 volts on A and D, as well as a ground on C. This is with the connector unplugged.

The weird part is that when I have spark coming off the coil wire(with ICM connector plugged in), I also have good voltage on pin B, but when the car dies and there is no spark, I hook up my spare opti and the signal is very weak on pin B. But ONLY with the connector plugged in. I can unplug it and the voltage is fine.

Intermitten problems SUCK!

Thanks in advance for any help!!

 

Possible that the opti harness has a broken or damaged wire?

 

Probably not, since I'm getting the signal from the PCM to the ICM. Maybe the ICM is failing when it gets hot.

Does the ICM have to be mounted to the coil bracket, or can it just be hanging out in the middle of nowhere?

 

It's definitely looking like ICM. I can heat it up and no spark... cool it off and I get spark again.

It actually gets warm with just the key forward... no idea why it would do that?!?! lol

 

heat will expand bad connecters also.check your wires i had stupid problems with worn connecters.

 

If its the Icm,make sure you use the di-electric grease on the back side.

 

It was the ICM.

 

You don't use dielectric grease. You use heat transfer grease (or more correctly, compound). Two different things.