I have an 350 cid TPI engine and 700 R4 trans from a '92 Z28 Camaro in my '55 Chevy. I am having an intermittent problem and I am hoping someone else has experienced this same problem.

All the wiring in this old car has recently been replaced, although the problem in question started before I rewired the car. The TPI ECM harness was not replaced,, or redone. The ignition module, cap, rotor, and coil are all new.

Whenever it feels like it, the engine starts running like the ignition wires just got crossed, with an occasional backfire through the exhaust. At the same time, the tach wigs out and ends up pegged out at 7 grand. This usually happens at slow speeds, under 45 or 50 mph. About three times back, it happened while sitting in my garage, at an idle. When this happens, I just turn the key off, restart it, and everything is fine, until it feels like screwing up again. With the engine idling, I've tried wiggling wires coming out of the ecm, and under the hood, and can't make the problem happen. It just does it randomly.

Any of you ever had or heard of this? Does it sound like maybe I should go through the expense of replaciing the ecm next?

Thanks for any help!

Chris