Haven't posted in ages, but in the last year or so, my VW 2l 16v running IB w/stock distributor has developed an increasing case of part throttle surging and/or bucking. I've been running the same tune for probably close to 10 years so my thoughts are that's not the issue. If anyone has any thoughts on what it may be (or how to diagnose), I would appreciate it.
Some pertinent info:
-Seems to be getting worse over time.
-It's the worst at part throttle steady cruise (~3000rpm)
-Recently changed plugs, plug wires, distribution cap and rotor with no change.
-Not running any kind of Idle air controller
-There is no way it's a plugged cat
-Not running any o2 input
-I have a fuel pressure gauge in the car and it remains constant through the surging
-I'm lucky if I make it through 1 tank of gas a year, although last year I did fill it up twice, and that seemed to make no difference
thanks for the help
(and just saw no more 034