My 1988 IROC-Z literally turned off while I was driving the other day and isn't starting. It cranks but doesn't fire up. I checked for spark and am not getting any at all. I immediately assumed it was the coil but I installed a new one and it still wouldn't start. The distributor appears to be in good shape, new cap, turning rotor and I haven't noticed any corrosion under the hood. I know the starter, battery and alternator are fine. I hear the fuel pump turning on and I just changed the fuel filter filter. I even tried putting fuel directly in the throttle body. I've seemingly ruled out the most obvious problems... Any ideas?

 

I would have the ignition module tested, but I don't think that would cause it to turn the engine off while driving. Possibly a VATS problem. Im not sure.

 

NOT a VATS problem ...

1) VATS disables starter, so starter would not turn
2) no VATS until 1989

Under rotor, in the distributor, there is the ignition module - I'd start with replacing that. Parts stores can test them, but it's a $30 part, I never bothered testing them.

 

My GTA did the same thing in the fall, and I couldnt figure it out, so I decided to pull the L98 and build a new motor. Upon pulling out the L98 we found that one of the grounds on the back of the passenger side head was pinched between the bellhousing and transmission, and was literally cut because it was pinched. So we figured it was that cut ground that was the problem.

 

ICM for sure. As said above, it's 25-30 bucks. If that doesn't fix it, then it's probably the pick-up coil.

EDIT: The ICM can cause the engine to shut off while driving. Heat kills them.