i have an 87 iroc with the 305 tpi. a couple of weeks ago it started loosing spark intermittenly, usually on my way home from work. Before that i had put a new coil and icm on it. One night it happened in my attempt to restart it my starter blew up into two pieces! I replaced the starter and it started fine so i left it running till it died again so i could find out why it was loosing spark. It eventually died and i discovered that the pickup coil was in bad shape. put a new MSD distributer on with an MSD coil. No spark. when i leave the key in the on position it will overheat my coil. I've replaced the ground strap and negative battery cables. The only spark i get is when i turn the key from the on position to the off position. The ignition switch seems to be working fine. Please give me some ideas as i have now come to a dead end. I suspect the pcm but am wondering if it's something more simple. Please help

What kind of Distributor is it? I know you said MSD. I have a accel breakerless unit on my 68. I added a MSD box to it and it wouldn't start. What I found, and would have known if I read all the intstructions was the board for the breakeless portion needed to be removed. I didn't do that and ended up burning the board up.

So if the MSD is breakerless and meant to stand alone the MSD box could have burnt something up.

no box on it. it's just the distributer and coil. no clue if it's breakerless

Does it turn over at all? Is the engine spinning I mean. Take the cap off the dist and crank it. Is it spinning?

oh yeah she turns over. just no spark.

Did you pull the cap. Is the rotor spinning too? I you threw the timing chain it would give similar symptom. Car turns/no spark. if you pull the cap off and spin it the rotor shoudl turn wit the cam.

If its not budging then you probably busted the chain. And you might need some head work if the valves got smacked by the pistons.

hmm... i didn't even think of that. i started to pull tha cap off at work but then i got busy so i'll have to do it tomorrow. good suggestion

it runs!!!!!!!!! FINALLY! it was the BRAND NEW icm that came with the BRAND NEW distributer. S.O.B. Thanx to everyone that offered suggestions and tried to help.:smiley_thumbs_up:

Glad you got her going.