I have very similar problem with my 94 Villager (250K miles). The hesitation / bucking happens during acceleration when the gas pedal is depressed slowly from a stop. When I floor the accelerator, it almost has no problem. It runs fine at high speed and idles fine too. I have replaced throttle position sensor (TPS), front O2 sensor, distributor cap, rotor, spark plugs. Also I have cleaned the mass air flow (MAF). I also removed the vacuum from fuel pressure regulator. Removed the vacuum from EGR valve. None of these fixed the problem. When the engine is hot, the problem diminishes. I had no check engine light. I don't think it is the injectors since it runs fine at high speed and idle. Also runs fine without load at any RPM. I think the engine control system is somehow faulty, but dont know which part causing it.
Wednesday, October 24th, 2012 AT 9:09 AM