Help!

1995 Blazer 4.3, Kid's car, died while driving home. New fuel pump. No spark.

Replaced...

Crank sensor
Coil
ICM

Still cranks, no spark at the coil. I have fuel pressure. I followed the test procedure here, still nothing. Part 2 -GM Misfire, No Spark/No Start Tests (4.3L, 5.0L, 5.7L).


PCM???? It's $30 at the junk yard so not a bad option but I'm stumped.

 

Distributor issue? Have you taken off the distributor cap yet? See if the rotor is still intached or if it looks good. Also crank the engine with the cap off just to make sure it still spins, that way you'll know if your timing chain broke or not

 

Cap has wires on the side (not round) is it still a mechanical rotor under there?

 

Distributor looks good. Thinking I might throw a $30 PCM from the junkyard at the problem??

 

New PCM and I now have spark and a short run up occasionally while cranking or with starter fluid. I can keep it running with starter fluid. It's almost like something is being shut down once it fires.

HELP!

 

is there any kind of theft light on? saying security or anything like that? another stupid thing you can try is if you have another set of keys, try using one of them to see if it will start. if youre in a quiet area listen for the fuel pump to prime while tyou turn the key on. might have to have someone lay under the truck to listen but it should buzz for 3 seconds. you can try tapping the tank with a hammer if it doesnt make noise.

but for both to go out at the same time that usually a crankshaft position sensor or other issue.

 

Nothing since that one quick run up. Re-did the test procedure for the coil, ICM, PCM etc using my meter and LED test lead. Swapped all new parts with old parts. There is no switching signal getting to the ICM or coil. Swapped ICM with old one. Found remnants of old auto start unit. verified not cut or shorted wires. clipped old wires that were tapped into the OEM wires to make sure there isn't a short to ground etc.

New fuel pump last fall, have fuel pressure and pump sound.

Still nothing