az0884

My opti was intermittently sending the signal to the ICM and I just got done installing a new ac delco opti and now the car wont idle on its own and the timing is reading 32 degrees advanced. I wasnt positive if the first issue was the opti sending the signal or the ICM receiving it but the opti was under warranty so I started there. Could the ICM be causing this or does it seem like my new opti is bad? It went on nice and smooth, didnt have to force it. Just lined up the key on the gear and popped right on.

az0884

Just changed the opti once more since I had a spare and now it idles good but still not drivable and still getting 28 to 30 degrees of spark advance. Ideas?

shoebox

The spark advance you are seeing is not a problem, that is normal. You must have some other problem.

az0884

Yea I think everything is pointing to the ICM or a bad connection to the ICM. The difficult part is I have a delteq setup and theres alot more wires invlolved and Im not sure what path to take for troubleshooting it since nothing matches up to anything Ive been able to find online.

Guest47904

Why do you think the opti could send anything to the ICM since the 2 aren't even connected. FYI the ICM is triggered by the PCM and it in turn triggers the coil to fire. The coil is obviously supplying voltage to the high voltage side of the OPTI. But the opti does not send anything to the ICM. It does send it's low voltage feedback side to the PCM.

Injuneer

The Delteq's don't seem to be all that reliable, but unforunately there is no longer any tech support or replacement parts. The fact that you have the Delteq would rule out the coil and high voltage side of the opti. Does the Delteq even use the stock ICM?

az0884

No it uses an ICM from a cadillac deville northstar. I had a friend with 2 northstar motors so we swapped out the ICM and coils but it made no difference. I pulled one of the spark plugs and it was real nasty so Im going to change all the plugs on saturday and see what happens.