Used my new timing gun, I would say timing is very stable at idle, now at 13 degrees with disconnected vacuum advance, might move an ½ degree if it moves at all.
Increaseing the idle speed a few hundred RPM does not affect the timing, stable at 13 degrees, putting gear into drive does not affect the timing either.
Tried to slowly block the carb in order to see if the idle smoothened out, but it got worse and was about to stall if I didn't remove my hand quick enough.
I see some fumes from the crankcase breater cap when EGR is blocked, so there is some amount of blow-by despite the compression test, is that the reason for the idle misfires?
Right now I have run out of ideas, is it ignition, air/fuel or mechanical related?
Here is a small video clearly showing the vibrations at idle:
