1997 Mercury Villager • 140,000 miles

I just had my oil changed. Now driving the car, my car appears to be chugging or bucking when in low gear, especially seems to be when changing a gear. So I let up on the gas until it runs smooth and just depress slightly until I reach higher speed. It does not do this when in higher speed - just when idle sitting long and starting out from a stop or slow down. Is it a fuel pump, ejector or spark plug problem? Transmission - though it seems to fnd the gear fine? Do I need a tune up? The check engine light is on - but in the past it has gone off and on at different weather changes. All levels are fine. Please help guide me. Thank you.
October 24, 2012.

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.

Oct 24, 2012.
Check to see if you spilled any oil on anything electrical.

Have the code pulled and get us that code so we can further help you.


Oct 24, 2012.
In my case on the 94 Villager, I have no check engine light.

Oct 25, 2012.