1995 Caprice Engine just quits

[wrenchman60]

My 1995 LT1 Caprice will run just fine, then the engine will stumble and die. Will crank, but will not start. Let it cool down 15-30 minutes. Will start and run fine for 3 days to a week then quit again. It has repeated this for 6 months. With 82,000 miles on the car I decided to look in the opti-spark unit. The bearing was bad. Installed rebuilt opti-spark unit, plug wires and plugs. Same problem. Replaced ignition module and coil. Same problem. Check fuel pressure 19 psi.
Replaced the fuel pump and filter. Fuel pressure is 45 psi key on, 41 idle and 48 with vacuum line off regulator. Same problem about 30 miles after installing fuel pump. Any ideas??

[KW Baraka]

Easiest and cheapest the to check is for coolent on the oil.

The cutting off and starting 20-30 minutes later could be a blown head gasket; cutting off results from coolent in the cumbustion chambers, killing the spark. It re-starts after the collent has drained out.

Also.....look for steam (white exhaust) coming out the pipes for the first couple minutes after you start up the car.

KW

[cocobolo95]

When you replaced the icm, did you use heat sink compound on back of icm and on heat sink?

Also check out the electrical part of the ignition switch located under the dash attached to steering column. It is common for switch and/or it's connectors to fail. Look for burnt wires, and connector pins, as well as, bent, corroded pins.