I have a 83', 1.9L fuel injected = Vanagon. I have replaced all engine gaskets, (including heads) water pump, = thermostat, fan switch, fuel filter, O2 sensor, piston rings, complete tune-up and = probably a half dozen other things I can't recall right now. I have also = checked out most off the sensors (coolant sensor #2, injectors, and etc) and = any others my equipment could do all checked out within specs. I used a = vacuum gauge to check for exhaust back pressure (cat converter) = looked good as well. The problem I am having is that the bus idles badly, = shaky like. When I take it for a road test it's breaking up at low RPMs = and when I rev it real high it also breaks up. It kind of sound like it is = running on 3 cylinders. Another item worth mentioning is that if I let off = the throttle just right it kicks in and sounds and runs like it should (much = quitter and a lot smoother). I had an exhaust gas analyzer hooked up to it = and the mechanic adjusted the CO supposedly within specs. He also checked = the fuel pump pressure and found it to be OK. Any logical comments are appreciated. Also the recommendation of a excellent VW mechanic in = NJ would be helpful!