driftpin

Thanks Ben! That was one of the first things I checked, all stranded! I believe it is misfires, as it does not produce a loud note from the tailpipe. But this is my first car older than 98’, so I am not nessicarily smart enough to know the difference

Thanks for the tips all! After reviewing the shop manual, my money is on the vacuum advance. I think the ignition & centrifugal advance are probably fine given that the condition does not occur at high rpm in neutral, only while under load. Now I just have to figure out how to diagnose and fix it! I received the car with electronic ignition installed, but I think I have the OEM in a box of spares. It looks like the plug wires are old, but no shorts, so I will probably just replace them and the plugs as a maintenance item if nothing else.

Hello all! Through good fortune and family, I have acquired a 1940 Buick 56S. It runs and idles fine, but under load it starts to misfire badly on what I believe to be multiple cylinders. The ignition has been converted to electronic, but is otherwise stock. Could someone help me figure out the right troubleshooting path?