5.0 efi in these trucks use a low pressure pump in each tank feeding an accumulator/reservoir and high pressure pump on the frame rail.
The ECU triggers the pumps for a few seconds and then waits for a signal from the distributor pickup to tell it that the engine is spinning.
This is a fire safety system.
You can find the fuel pump wiring under Documentation/Electrical/EVTM's/1986 EVTM
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.