First I gotta say this is not a thread to rag on Pertronix ignition, I'm wanting to get some feedback as to a problem I'm having with my 63 Riviera that I think is ignition related. The car is a mechanically stock 1963 Riviera with the original 401. The engine has an early Pertronix Ignitor setup, installed in 1994 by a previous owner, which has run flawlessly for the 10 yars I've owned the car. Last time when I tried to drive the car it cranked over normally, started, but instantly would rev and die back, rev and die back in cycles of a couple of seconds. If you try to let it idle it will die after a few cycles. If you raise the engine rpm it will stay running but still cycles up and down at the same rate. The revving and dieing cycle is only a couple seconds long so the engine is rocking violently. To me it seems as if the ignition is cutting on and off instantly. What I've checked: wiring to and from ignition switch and coil, resistance of coil and plug wires, taken sparkplugs out to examine and made sure #1 cylinder is at TDC and timing mark and dist. rotor match up (statically timed), made sure fuel lines are clear from tank to carb, fuel pump output is good. When the engine is running/surging there is no backfiring either thru the carb or exhaust. I think either the ignitor unit is switching on and off or the coil is shorting out. Any thoughts or suggestions? Thanx!