My 1969 Swinger 340 has an intermittent, one time miss/cutout which causes the car to jerk. It seemed like the ignition system cut out completely for a second. It always happened when I was cruising back roads, at about 2,000 RPM. This was nothing like a spark plug misfire. At first, this occurred once in a while.
When this first started happening, I had a Pertronix, Ignitor III and coil installed for years (the ballast resistor was bypassed).Thinking it was the Pertronix, I switched back to the dual points, condenser, ballast resistor, coil and spark plug wires.
These changes worked fine for months, but the intermittent issue returned. It got worse when immediately after the miss, the engine died but would start right back up. Just before I stored her for the winter, the engine missed and died, but then it took 3 or 4 tries to get it started again.
Is it possible that there is an intermittent short in the ammeter, ignition switch, bulk head connector (which looks fine), engine wiring, etc? I believe the ignition system is properly grounded, including the distributor hold down clamp.
It doesn’t seem to me that a bad alternator would behave in this manner or that it is fuel related. Since the problem only lasts a second, a multimeter wouldn’t seem to be useful.
Are there any words of wisdom to share out there? Thank you.
