I cannot get my truck to start. New battery, and I know the engine receives spark because it starts and runs 5 - 10 seconds on starting fluid, but won't stay running. I can hear the fuel pumps in both tanks and on the frame run, but I don't think they're providing proper pressure. When the fuel pump is primed (by putting the key in "on" without starting the truck) multiple times, it'll start and run for a few seconds. This has lead me to believe that the fuel pump works, but isn't supplying enough pressure. I'm assuming I can just replace the frame mounted pump (because I'm 80% sure that's the one with a problem) with one from a scrap yard.
Am I correct? Find same year and engine and pull the fuel pump & I'm golden?

 

The frame mounted pump was the same for all engine sizes and the years that used them (~1985-1989 F-series).

I am not saying that is your problem however as I do not have enough information for that determination.
Could be the FPR, filter, socks or ???.

 

you can buy a pressure tester and hook it up on the line at the motor and that will tell you whether or not your pressure is good.

 

Have you tested your FPR?

 

I had the electric connections on mine come loose. Be an easy check and cheap fix.

 

Bought one from scrap yard today, taking it back tomorrow because it was blown, but the truck refused to even sputter, leaving me to believe the fuel pump is part of the issue. A friend of mine pointed out that the fuel filter could be clogged and that's 100% of my issue. Possible?
In reply to your very welcome help:
*Haven't dropped tanks yet to check the socks, it's on the to-do list.
*No clue how to check the fuel filter, only have vague idea of where it is (after frame-mounted fuel pump in-line?).
*Electrical connections do look iffy, held on by tape.
*How do you check the FPR?

 

There should be a fuel filter mounted beside the frame pump.
Note there might also be a filter inside the selector valve.