Tranny experts please

93 LX 3.8 automatic, The tranny will shift really quick when i am getting up to speed unless I keep it floored, which I do not like to do.. Also, if I use OD it will pop in and out of gear at interstate speeds, if I keep it in drive, everything works fine, it just uses alot more gas.. And it uses about a 1/4 tank of gas every 45 miles, could this be related to the tranny problems? Am I looking at a replacement, rebuild, or just a good flush?

When you say it shifts really quick do you mean that it goes from 1st gear to 3rd really quick. If so wouldn't that be a good thing. I know that if it shifts slowly like delayed shifting it's not good. My new car goes from first to fourth gear pretty quickly and picks up quick. That is normal. My thunderbird shifts pretty quick also. In the thunderbird forums that is why they modify the transmission valve body for quicker firmer shifts. If you need more info on that you should join the boards at www.tccoa.com they will be able to give you a better answer on that.

most quick shifts are caused from a broken piston/plunger spring or check ball spring in valve body . flushing probley wont help, if the piston/plungers or check balls are sticking or hanging up, it wont want to shift. also, check the torque on the valve body bolts, if you or someone else has changed the trans filter befor and got the bolts way to tight, it will effect the shifting

By design transmission should shift up to 3rd by 25mph.......falling out of O/D at highway speed is related to element ,,,,,clutch or band used to give o/d.....not applying properly...
you need to know which trans is in your car...helps determine what to do....tranny-in-a-can,,,,filter and a flush,,,re-torque of valve-body,,,,,looking for missing ck balls ,,,,changing blinker fluid,,,replacing winter air for summer air in tires will not help..most cases will require total dissassembly ,,certain models {A4LD}servos can be serviced without trans removal........