91 camaro rs 3.1. Check spark from coil and I have spark turn it on runs perfect for 1-10min then dies randomly, I check spark again from coil and I have no spark, replaced ign coil, pickup assembly, icm twice each. Still no lead way I let it sit for an hour and i have spark again but it does the same thing. Just replaced ignition switch and didn't help at all, tried disconnecting battery didn't help but I did have spark as soon as I connected it back, checked all my grounds scraped the metal to get better connection. New plugs wires... Security light doesn't flash and it does crank but it won't turn over. Obviously exactly what it does when everything works but whatever's causing no spark Thank you for your time. I desperately need help.

 

Check/replace the two wire pigtail that goes between the coil and the ICM. They are known to have the wire break inside of the insulation. Looks OK, but is bad.

The break is usually where the wires exit the coil end connector.

RBob.

 

I checked with multimeter and had connection even when I wiggled it on both ones I'll check again and try, I can't find just the wire anywhere autozone just sells the plug into the icm. Any ideas?

 

I have the wire RBob is speaking of if you need it.

 

Isn't That wire I checked again and it's just fine. I checked the grounds and they're all fine. Any other ideas?

 

I had a similar issue in a 92 3.1 rs. After a strange turn of events i ended up grabbing the ecm just right with the key on and everything turned on. If I gave the ECM a slight flex the car would start and run. That's a pretty wild and out there idea though.

When you replaced the ICM did you use the white heat sink paste underneath it? I have heard of instances where people replace them and they go out shortly after due to heat.

 

I had an issue were it would turn on run for one second and turn off. And would turn off when i would slow down ... Turned out the bolts on my battery posts were loose. Its soetimes something simple