Just a game

I figured this one out two years ago, but I thought I'd post here and see what you guys would have done.
"My car starts and runs great. The problem is that it stalls about half way through third (when I'm beating on it). Then I lift and it comes right back. It started doing this off and on recently. It's a B/RB 4speed car"
Ok, it took me two steps to figure this one out, shoot me your best two guesses.
Author: Mr.4spd