I hope this isn't redundant for the both of you, but
change your filter and fluid first, including the torque converter fluid. Then, disconnect your battery for 5 minutes.
Test drive. It should be corrected.
Re-program tranny manually see:
www.allpar.com
or get a dealer to do it for money.
Also, make sure your radiator fan(s) are working. Could also be the fan or fan relay...
Always use ATF+3 if you pour dexronII,III, OR IV in these transmissions, even just once! If you do, there's nobody who can help you avoid a $2000.00 trans job.
The solenoid pack can be changed independently of having the trans rebuilt, and the screen filter in it will clog, and stick the solenoids. It has been done, but cleaning the solenoid pack and getting it back together correctly is hard to do, and can screw up your trans if not done right. Changing the fluid and using fresh fluid tends to clean out the solenoid pack, not to mention the rest of the trans... and solve many troubles.
Again, I would hope that you knew all this already, but if not, I hope I can save you some dough!
Try it. ATF+3 and +4 both have limited lifespans and the trans won't take any other fluids, or fluids that have broken down, or become tainted with normal wear deposits.
Don't trust a shop with one of those trans cleaning machines. You'll be sorry if you do.
Slantsixness