I am trying to find out what is causing some misfires on my 87 gta, I have done all the normal things, compression, fuel pressure etc. etc.. just going down the line for ignition troubleshooting.

I really have not found much info on the spark control module as far as people testing them. This is NOT the module under the distributor cap, it is by the brake booster.

What would symptoms be for a failing unit, how can I test the module?

Here is what I am talking about.

Thanks.

 

The only field tests I'm aware of are comparing ignition timign in normal mode versus bypass mode, tap-testing the detonation sensor, and installing a resistor in place of the sensor to compare timing offset.

 

Is it possible?

That a knock sensor can adjust the timing in your car to the degrees that it would cause a misfire?

Anyway, that was the question I asked myself after my rebuild, and having gone through all the checks you mentioned and trying to resolve the problem.

I had put a bigger cam in the car, while rebuilding the engine. And upon starting it getting it to idle, would get slight misfires.

Changed the knock sensor and the problem stopped...Not that this is going to help you in anyway. I honestly have the hardest time with these sensor operated engines. To me it is automated performance tampering and at times I wonder if it hurts more then it helps.