1991 Honda Civic 1.5 L. Engine died, no spark. Coil primary and secondary are fine. Pulled the ICM and tested it at Autozone, failed the current test. Installed new ICM and it fired right up. Let it idle until warm power off and no restart. Let sit 20 or 30 seconds restart okay. Checked spade terminal connections and they looked good. Changed ICM with the same behavior in new ICM. While running all is well, just hot restart is the problem. Suggestions?

Replace the coil, too. Bench testing coils is virtually worthless, since it doesn't simulate the extreme heat they are subjected to.

Good suggestion but... New coil, distributor cap and rotor and still the same condition. If engine does not start while warm wait 30 seconds and try again, usually starts. I still blame the ICM but I think I am done throwing money at this. It is 21 years old, looks rough, the throw-out is squeeling, the cv joints growl and I can hear a rod complaining. It is time to recycle it. I has served my family well and I have no complaints.

Did you apply silicone heat transfer grease to the back of the new ICM?

Yes, the ICM came with a mylar tube of the stuff. I traced the harness assembly (in the distributor) looking for problems and everything is high and tight on that. Since two of the ICM modules behave the same way, the likelihood of an internal electrical intermittent is remote, that with the fact that while it is running it is solid. I figure the ICM is some sort of state machine. Do you know what signals are being processed? There is a ground and then three other connections. I figure one is the coil the other is the cam position sensor and the third is just power. If it is a solid state gate array could I be dealing with a programming issue?

The BLU wire goes to the tachometer.

Thought I ought to get back to this. Operated the vehicle with Duralast ICM for about 3 days with no improvement to the hot start issue. The behavior was predictable and repeatable: on no start, wait one minute and restart is immediate. Then another issue was noticed, the tach would drop out completely or bounce around erratically. Pulled the ICM again, replaced it with a NAPA part (cost $80.00 vs $50.00 for the Duralast) and all noted problems are gone. Autozone was very polite about refunding the cost of the ICM, as they have been for the 15 Duralast alternators that I got from them for the same car. Good thing I had a lifetime warranty... the most recent alternator is from a different supplier and seems to be a keeper (knock on wood).

I think I am through with Duralast. Everything else from Autozone is spot on...

Nice job. Thanks for the "heads up" on AutoZone's ICM--that's the first reported problem I've heard of.