Misfiring Engine

[1964 S1]

Hello Brian, yes, connection problems or failing battery. On more than one occasion with my +2, the headlight stalk has been flipped to the "on" position with the headlights down in the daytime, unbeknownst to anyone, draining the battery just low enough to start the car but then the engine will only perform normally in the lower RPM ranges as I nurse it home. If I get on it or try driving at higher RPMs the thing begins misfiring and sputtering, fouling the plugs, too much fuel for the spark provided is my conclusion. After trickle charge overnight on the battery, everything returns to normal. I was also thinking generator output/loose wire could be Vanden Perre's problem. Weak spark... ?

[Vanden Perre]

Thanks to all of you for your answers.
I have started the investigations last week end. I bought Champion N7Y CC spark plugs and have tested them. No real difference. I keep trying other things.
Olivier.