My 83 rx7 just won't go into reverse, so ive been asking everyone for there advise on taking out the tranny and when i started doing so today. I took off the tranny plug for the transmission fluid no fluid came out of the tranny. Do any of you think this could be the reason why its not going into reverse????

 

Absolutely!
I ruined one once by not getting the drain bolt tight enough, fluid all drained out.
Be sure to go ahead and get a new drain bolt AND gasket when you add new fluid.
Also, go to the nearest GM dealer and get 3 quarts of GM syncromesh. About $9 a quart, but it's worth it. Don't put the cheap stuff in.