Are you sure the problem is the transmission? Sluggishness off the line on these cars is often due to factors like injector pump wear, so unless you've counted the shifts and determined it's really starting in 2nd, I'd look there first. Remember the old saying about automatics, "if it runs wrong, it'll shift wrong."

If this is a turbo, I would check in particular for a clogged ALDA line, and maybe try adjusting the ALDA.