Hy tracern1, I doubt the Pertronix has anything to do with the problem, the fact that it runs in some circumstances would tend to say the Pertronix is doing its job. I would check the ignition circuit with an 1156 bulb or a headlight, many a circuit that reads fine with a digital meter actually has very little amperage capability. From what you describe I think the bypass circuit fed from the starter is the only part of the circuit that is functioning correctly.