92/94 Transmission stop shifting until shutoff, restart...

[Intuit]

Come to a stop or slow to a walking pace, and the vehicle tries to go but doesn't. The engine RPMs just rev-up with intermittent slip-grab from the transmission. Engine checks out fine and we haven't tried to pulled any codes.

Runs fine cold, only starts to do this after you drive it around the block. If you pull over, key-off, then immediately key-on again, it'll start off perfectly fine and take you to the next stop before it happens all over again. Never stalls, even when stopping and the engine never bogs down. Just key-off, key-on, and good to go.

Transmission was supposedly rebuild < 1 year ago.

What are the typical issues with this transmission; what needs to be replaced ?
What electronic portions of the transmission, could be responsible for this ?

We don't have access to a scanner to pull codes. Taking it to the nearest parts store with a scanner, risks getting stuck somewhere which means $100 tow.

Mileage: ____
Engine: _____
Year: _____