tireboy

i have a 91 chev 350 auto tbi. lately the truck wont stay running sometimes it takes about 5 tries for it to stay running . tonite it lost power climbing a small grade n stalled. fired right up n no issues for a few miles .so far the fuel pump has been changed and also a new fuel filter. no engine codes have come up . no drivability issues . missing n backfiring .tons of power when it stays running . it did the same thing a few months ago and went away ... seems kinda odd ... any suggestions????? i will be replacing the wires cap n rotor n plugs tomorrow ...any help would be greatly appreciated... thanks in advance...[][:'(]