Help! I have a '86 Chevy PU with a 305 carb engine. I have been having trouble with the ignition system. I have replaced the ignition switch, starter, Coil, pickup coil, module, harness, etc.-yet I still have intermittent spark! At times it cranks right up and then shuts down. A spark test produces no spark. Later, I will try it again and it fires up, with a strong spark. Could the Electronic Computor Control be involved? The driven gear? Please help. I am a grad student and cannot afford to take it to a shop. Thanks!
agar521

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agar521

 

Check the pins at the ECM connector and the four wire distributor connector that terminate the four distributor control wires at each end. They may not be making good contact with the ECM pins or distributor module pins. Individual replacement pins for the ECM plugs are available from Fuel Injection Specialties (Texas), and probably from GM, as well. The four signals are reference (purple / wht), reference ground (blk / red), EST (white), and bypass (tan or tan / blk).

Tim