1987 740 GLE B230F
OK, engine starts and idles just fine - sounds good.
While idling I either turn the throttle assembly by hand under the hood
1/4 turn or barely push the throttle. By doing this the engine seems to
choke out for about 1-2 seconds then picks up with a normal fast idle.
I did this repeatedly, barely turn the throttle, the rpms dip, then
pick back up.
Idles -- dips -- picks up.
Instead of going from idle to fast idle, it's like it chokes a moment
I just had the timing belt and all seals redone with new crankshaft
Does this sound like timing? Vacuum? Fuel Filter? Other?