Always check for vacuum leaks with a stall situation, especially when heavy on the brakes.
Second...and less common, is a stall situation when cruising along straight line, no turns, even gas input, just maintaining speed....and she quits. I have seen bad spark plug wires arch enough to shut down the motor, roll back the key, turn to ON position and comes alive again. It took me a year on my sisters audi 4000 to figure this out. Dealer could not find, indy mech could not find. Could never reproduce in a shop. FYI..wires were only 1 year old, and broke down real quick for some reason.
Moral is.... every once in a while, open your hood at night...pitch black, and see if you are getting a light show.