I need some pointers.

2001 f150 lightning starts on the button , idles for a few seconds and then dies.
If you keep your foot on the gas the motor surges between 3750 and 500 rpm.
The truck ran fine until parked up for a few months. It ticks over fine on starting fluid. Pump ? fpcm?? HELP

 

More than likely it's the fuel pumps, it has 2

 

I think the fuel pump pressure is supposed to be 50 something P.S.I. If it were me I would have it diagnosed instead of becoming a parts changer which can get expensive.

 

I'm late to the game here but I'd do a visual look-sy under the hood. Any critters around your place eat up any wires or vacuum hoses?