Hey guys, it is me again and i am still fighting that miss in my 94 z28 6 spd. I put a new coil and coil wire on this afternoon and it seemed to help a little. What does the icm do exactly? The miss does not develop until the car is up to operating temperature.
I checked my water pump and the weep hole was dry right after i drove the car. It only misses or makes a noise like a carburetor engine coughing back through the carb. (but not everytime). It feels like it is missing and i hear detonation sound like a 70's car running on unleaded. Original plug wires and I checked the driver side wires at the optispark and they "looked" good but I know that does not mean a lot.

Please reply with any input or help,
Thanks a lot everybody.

 

The ICM receives pulses from the pcm and then signals the coil to fire. It can be affected by heat if there is a crack in it or maybe a marginal circuit tracing or component inside it. The optical sensor in the opti can be susceptible to the same thing, though you should get a trouble code in that case. There are some auto supply stores that supposedly can test the coil module.