1987 Ford F-150 Fuel pumping problem

The relay may not be coming on. What motor do you have as they have different fuel requiremnets.

It is a straight 6, but I am not certain on the size. The guy that owns it does not remember and I am not close to where it is right now.
Will this help, or do you need any other info>

Thank you, Chuck

The 6.9liter is a beast in its self. It takes 60 psi to just start it. There are 2 pumps, one in the tank and one under the drivers side door in the frame rail. The one undre the door is the pressure pump. Try grounding the test plug out under the hood. It will be the bottom slot on the right side of the plug. This is a mobile test that runs all the pumps. With it grounded listen for the pumps to come on. If they don't then the relays bad! If they do but still no pressure at the engine, switch to rear tank and clamp the retuen hose off to the front tank as I have seen the valves stick at half open. This makes the gas just flow between tanks and not to the engine itself. The valve is pressure switched. The switch on the dash just changes the pumps from front to rear and the pressure changes the valve route. I hope this helps.