transmission question

[stephenC]

I just got a 96 explorer for next to no $. Even if I have to replace the tranny, it's a good deal. There again, don't want to if I don't need to. The problem is when I'm doing 70 and apply gas, the RPM's increase, then begin to decrease again, without my letting off of the gas.

I have no basis of comparison for this car, as every car I've owned has been pre 1957, or a standard shift.

There are no other malfunctions, no lights, nothing.

Any thoughts?

[speedindevil]

Could be a few things, fuel filter, pressure regulator, maybe even MAF, does it do it any other time at other speeds?

[Opera House]

If the change is about 300 rpm it is probably the torque converter clutch locking and unlocking. I would check the throttle position sensor. These get intermitant in the range they are usually at. Trans could be thinking you are trying to accelerate.

[stephenC]

Where is a throttle position sensor, and how is it checked? Thanks!

[Opera House]

The TPS is located on the engine under the throttle body cover. A black device with three wires. A voltmeter is connecte to the center wire and one of the others. The throttle is then moved and you look for a smooth change in voltage.