My 92 F250, 5.8L, will start and run for a few seconds, then dies. I replaced the fuel filter, and that didn't work. HELP!

 

Sounds like the high pressure fuel pump in the frame rail. The pump in the tank runs for 1-3 seconds after startup, that's it, then the pump in the frame rail takes over.

That's if your truck is the same as my 1988. Not too bad to get to or change out. The pumps in the fuel tanks are a lot more of a job.

 

Incorrect. The trucks with the dual fuel pump setup run both pumps, all the time.

It does not matter anyways since 1990 and newer trucks got rid of the high pressure frame rail pump, and just have a pump in the tanks.

As to the OP, I'd start by giving it a little gas when it starts, and see if it keeps running if you feather the gas pedal. If it does, then I'd suspect the idle air valve is stuck closed.