Here is a mystery. The car is an early 71 that is essentially stock, but I run a header and a Mallory dual point mechanical-only distributor.

It starts great every morning and runs well for about ½ hour. Then I get a stalling effect. It is as if one turns the key off and then quickly back on. It happens once or twice at first but then gets more frequent as I go along. I had this problem before and replaced the positive and negative connectors at the coil and it went away. Now it is persistent.

By the way, it only affects the engine – voltage does not drop, the lights do not dim, etc. when it occurs.

Any help is greatly appreciated.

I had something like that happen to mine. The problem was the wire going to the dizzy would short on the exhaust manifold. I have since re-routed the wire to keep it way from the exhaust manifold. Just a thought. Also, check the terminal fits on the contacts for the entire ignition system (wires going to resistor and coil). Make sure they are clean and snug.