1995 Mercury Cougar engine shifts sparatically while drivi

This happend to me to the problem was the( high range imput sensor)

While driving the vehicle it seems as the engine revs without any acceleration and then goes back to normal. Taking it out of overdrive does nothing. I have had the transmission checked and cleaned from a Mercury dealer and they state nothing is wrong with the transmission and could not diagnose the problem.[/Quote]

[/quote]

I have a 1994 mercury cougar that was doing the same thing. I researched and found the problem to be the manual lever position sensor which is mounted on the side of the transmission from the gear shifter. After replacing this, still working fine.