91 celica tranny trouble

I have a 91 celica gt that's giving me trouble shifting. Tranny is auto and shifts at high rpms which I know is common in these cars but I recently got in and she wouldn't shift at all(the car ran all day fine, but this happened after it sat for 4 hrs and engine wasn't even warm) Fluid was low when I checked it and after putting a quart or so in it was shifting smooth without any hesitations. There is no leaking visible when running or spots under it, so where is my fluid going? Has anyone come across this issue or have any advice on what it could be?

i hear your pain lol. My 92 GT (auto) is doing the same thing, mostly in the mornings when its been sitting for a while. It seems to have to warm up before it will shift past 2nd gear. As far as i know my tranny fluid isn't low though, but ill go double check.