Hi all, new user here. 1994 Mazda MPV 3.0, 2WD, automatic (148000 miles)
I have one of those weird problems that can drive you crazy, and do hope someone can help.
At speeds lower than 50 mph the van runs absolutely great, but when I exceed 50 mph and begin to let off the throttle a bit in order to pace traffic it will suddenly feel like I let off completely (get a little stutter at this point) and upon re-engaging the throttle I get a jerking or stuttering until I bring the motor up to the speed of the vehicle, at which point it again runs perfect. This happens virtually every time I go above 50 and attempt to slowly bring the cars speed down. Also the power appears to be a little lacking but that may be normal for these vehicles, not sure about that as I can only compare it to the power of my 93 Ford Ranger with the same size motor and auto. trans. which is considerably more powerful.
I have replaced several things I was told could be the problem:

1. Fuel filter
2. Air filter
3. Mass air flow valve
4. Heat sensor unit
5. Destribiter cap and rotor

My mechanic checked everything he could, and found nothing else out of spec.

1. Fuel pressure
2. vacuum pressure
3. spark and spark plugs

I do hope someone has an idea just what is going on, and a possible remedy.
Thanks

 

What gear does this happen in (ie OD, D, 3, 2)? Try taking it out of overdrive (OD) and see if that cures the stutter/jerking at that speed.

 

Thanks for replying to my problem, Mozdatirol;
I did try it with the OD disengaged, and the problem continued. It has my mechanic stumped also that is why all the parts were changed per his investigation with no luck, Although the heat sensor was bad and changing it corrected another problem with cold starts.
Again thanks
Manny