I have a 1993 Pontiac Grand Am that runs great except for an annoying occaisional quirk. After operating for awhile, the transmission will not downshift when coming to a stop, and stalls the engine. I have to put it in neutral, start the engine, rev it, and shift into low to get moving again. It is a floor shift, 3 speed automatic, After it sits for awhile, it is fine. Trans fluid is at the proper level and looks/ smells fine, would a new trans filter help? Thanks.
If it acts like a straight stick with the clutch not disengaging, I would suspect the torque converter lockup is not releasing. Their is a solenoid that controls it and most likely this needs to be replaced. Its under the transmission housing cover under the hood so just depends how hard it is to get the cover off as to cost. The other thing you can do is disconnect that square four wire plug on the trans housing and that will disable the lock up. You’ll lose mileage but at least can confirm that that is the problem. Then get an estimate from a non-Ammco trans shop, that’s an ATRA member and see if you want to replace it.