I have a 1983 ford f250 with a 7.5L 460 ci 4 barrel carb. within the last month i have been able to start and run this truck. within the last week it would start, but only after spraying carb cleaner in the carb.

why is there no fuel being pulled/pumped into the carb? i have filled the floats with fuel, started the truck, and it runs for about 30-45 seconds (until the fuel in the floats is empty). While the truck is running for those 45 seconds i have been pushing the accelerator as well to pull fuel from the fuel tanks (they have gas in them), but after 45 seconds the engine still dies.

thanks

 

I would first check the filter and then the pump.

 

Check fuses and relays first, then make sure battery holds a charge, thenstart your truck with the battery fully charged and completely connected, while the truck is running, disconnect your positive battery cable, if your truck shuts off, your alternator may be faulty, if it stays running, reconnect your positive cable to the battery, and find a wiring diagram and someone who knows how to read it, chase wires until you find the short, make repairs as necessary