My supra has sat for a couple years from lack of fun money. I bought it running but no reverse. I can start it up and everything but I dont know enough about automatics to have any idea what is wrong. The only thing i can think of is that something is loose or the tranny computer is messed up. Any help would be great. Thanks

look under there and check to see if everything is tight? if not probably roasted trans

In all automatic transmissions, reverse is aquired by holding the carrier in the planetary set.

Look in the powerflow chart to narrow down what isn't working.