I have a ‘62 544 with a B18D, old style crankcase ventilation (direct to pipe on side of block),
VJU4BL33 distributor with vacuum advance. Runs fine at idle, but as soon as comes off idle It gets real jerky and starts stumbling. I tried driving short distance and not even drivable.
I thought it was fuel-related, like not getting gas once off idle, but then I tried removing the vacuum advance line, and suddenly seems to run fine - no stumbling - as I “blip” the linkage and rev it with no advance. I don’t know how close reving it in the garage is to running under load.
I haven’t tried driving it without the advance yet. I wanted to know if anyone had any suggestions.
Speaking of advance, with cap off I can turn the rotor slightly CCW, but not very far (I am afraid to force it) and it snaps back smoothly. The vacuum advance arm moves the plate freely but I don’t know how to tell if it’s working right while running.
While I’m at it, why is there a tiny braided wire running from the vac advance diaphragm unit to the plate? I just don’t see what that process has to do with electricity but then what do I know? Is it just a ground? Anyway, appreciate any thoughts or ideas anyone might have!