So I done some work on my fiero (v6 2.8), I changed exhaust and distributer cap and rotor. And the car started fine and I had it running in the driveway. Car ran perfect and then started sputtering and shut off.i guessed it was coil or feel filter so the next week I changed both. (Fram and msd blaster) the car started and Ran perfectly again. I went for a quick ride then back home and shut the car off. Tried to restart and nothing. I checked for spark and nothing. I have the msd box (was on the car when I got it approx 5 years old) I'm wondering if it's the box or something else?
I had a similar issue when i first purchased my 86se many years ago. turns out i had over- gapped the plugs. it put extra strain on the coil so it would heat up and stop working. every time it cooled down it would start like new.
Well in the very recent past you could take the old ICM to parts stores like Autozone or Advance and they had a machine to test ICMs. The trick was to test it 2 or 3 times to get it very hot. I have read a thread or two where folks say these testing machines are becoming harder to find. I'd suggest calling around to find one before heading out.