the truck runs for about two seconds then stalls, the fuel system and electrical system seem to be ok, what is going on?

 

What do you mean by "seems to be okay"? Have you done any tests? It sounds to me like low fuel pressure. Take the gas cap off and listen at the tank while someone turns the key on (not cranks the engine, just turns it to the "On" position. You should hear the fuel pump run for just second or two as it primes the engine. If you don't hear anything, check the Inertia Switch to see if it's been triggered, it should be located in the passenger side footwell right by the transmission tunnel sort of at the top edge of the carpet or floor mat, almost up under the dash. See if the button is sticking up or if you can depress it and click it back in.

If that's okay, then you need to look at the fuel pump fuse and the fuel pump relay. If those are good, then you probably have a bad pump.

If on the other hand you can hear it run when the key is first turned on, then you need to check fuel pressure to see if it's adequate. You can buy a cheap fuel pressure tester from Harbor Freight for about 15 bucks, it connects to the Schrader valve on the fuel rail. Turning the key on to prime the system should give you a minimum of about 35 PSI, if it's below that you may have a plugged fuel filter or a weak fuel pump.