Ok, I have searched without any luck finding a post with my same problem. I have a 1991 firebird w/ 305 tbi. last month I went to get a hair cut and after i came out the car would not start. I noticed that the fuel pump wasn't priming so i had it towed home. after checking fuse, relay, and pump connector behind gas tank everything checked good but would not prime, so i gave up. came out later and it started right up. ran for a month without no sighn of pump failure. drove to work last week and parked the car , then when i went to leave, no fuel pump prime again.kept messing with the wires thinking i had a short, unpluging relay, pluging it back in, same with pump connector behing gas tank, unplug-plug back in so on & so on. then it started out of the blue and ran great, thought that it was fine turned key off and then back on and no fuel prime again. car ran great when it did work. bought new relay-(no luck) then jump fuel pump on connector at relay (orange to grey) put a multimeter at connector behind gas tank 12+ volts at grey wire 6+ volts at purple wire, but pump wont prime. do pumps just work great one time then not at all the next without hesitation? thinking of replacing the pump but it seem's like a pump would give notice of going out while running no just stop like it has? any clues???

 

Next time it wont prime try turning ignition off for about 15 sec. cycle key a few times wait another 15 sec. turn ignition on and listen for prime, this should work. I have to do the same to mine sometimes. Not sure where the problem resides but am thinking in the ignition circuit somewhere inside the steering column.