I experienced similar symptoms right after finishing an install. When I reversed the two wires that come from the distributor and all was well. I reversed them again and the engine ran poorly. I switched the wires back again and the engine ran well. I think it may have something to do with a sine wave trying to efficiently run the HEI module that is looking for a square wave. Don’t know for sure that i’m correct on this, just guessing.
Jerry in Denver
