I have an 89 IROC 5.7 TPI with an intermittent no start problem. It cranks over but doesn't fire up. This problem has been going on for years but seems to be getting worse lately. There doesn't seem to be a common condition during which it occurs. It happens when hot or cold. I go to start it and it just won't fire. (it seems to start for my wife though!) It has never died when running. It doesn't miss, stumble or anything else.

This has been very difficult to diagnose because it seems that about every time I go to troubleshoot it the dang thing starts! When I have had a chance to test it I've connected a spare spark plug to the #1 plug wire with jumper cables providing the ground. There is no spark while cranking. Most of the time it will crank indefinatly with no spark. Sometimes I'll get a couple of weak sparks, then it will start. Come back in a couple of hours or days and it will start and the problem seems to go away for a few days or weeks.

Over the course of a couple of years I have replaced the pick up in the distributer, module, coil, cap and rotor, plugs, wires and ignition switch. I have checked VATS, grounds, electrical connections, fuel pressure and everything is within specs. The coil is a Mallory external and the rest of the parts have been parts store replacements. I have run the normal checks like resistance tests on the coil and plug wires, verified power to the coil during crank, have had the module re-tested, disconnected and reconnected every connection I could think of and the problem is still present.

I'm to the point of re-replacing components or taking it to a dealer or somewhere but since it occures only once in a while, I figure they'll have the same problem running it down. I am willing to go back over everything again and would appreciate some suggestions on what the most locical proceedure would be. I'm probably overlooking somethins or making assumptions. Any suggestion???