1984 Pontiac Firebird Fuel Pump?

Sounds like it could also be your transmission fluid is low. You should check you transmission fluid level and check for leaks. May be the fuel pump like you said too though.

I know what your problem is mine did the same thing it would hesitate and then all of the sudden just romp check your carbureator if not that then check your throttle cable if it is loose it will do that there is a button on the cable valve that can be moved up or down to tighten the cable