According to my schematics, you have a fuel pump cut off relay and an inertia switch. From '84-'86, the first years they put an electric fuel pump in the F150, they called the fuel pump relay a fuel pump cut off relay. Starting in '87, they changed the name to fuel pump relay. They are exactly the same, in the same place in the circuit, serve the same function, and even have the same color wires. In 1987, the diesels had a fuel shut off solenoid, but that was totally unrelated to your truck.
What color are the wires going to the two relays you say are for the fuel pump?