when the car been setting for a long time,such as overnight the trans will not shift into any gear.the shifter moves freely and engine rpm drops as if the converter engages but the car will not move until the car runs for a couple of minutes.yet there is no sign of slippage or burnt fluid. thanks

How old is the fluid and filter? Have the oil pressure in the transmission tested.

the past owner had the fluid and filter changed prior to the sale.I know better than to trust someone I do not know.Once I change them and if there is no difference is a pressure test as simple as an inline gauge to the fluid cooler? Or is it time for transmission swap?
thanks polaris1

There should be a oil test point on top of the transmission near the shift linkage.

Typically this is a bad seal or input piston.

thanks for the info will test pressure and check out the input the input piston.
polaris1

oops,my to bad my replies are not correct

I agree.

I learned from one of the best.

the fluid pressure is 70psi after setting overnight,is this correct?if it is where is the input piston located?can it be checked/removed with the transmission in the car or is it.or does the transmission have to be removed?
thanks again
polaris1