Where is the fuel pump and which relay goes to it? f150, 5.0 efi-

Check distributor rotation to ensure good timing belt. If good, check crank and cam position sensors. The computer fires the plugs and injectors based on many factors but most importantly the crankshaft and camshaft position.

Lets start at the beginning. The engine computer grounds the pump relay. The relay gets power from the EFI relay when the key switch is on and from the starter fuse when the key switch is in the start position. Do you know if the pump relay is getting power from both sources and a ground from the computer ? Can you run a hot wire to the blue black wire going to the pump and keep it running ?

I don't think the EFI relay is at fault. Other things would be dead if it was, including the starter. See here p177 to test fuel pressure, which may be too low if the fuel pump itself or the pressure regulator is faulty.

http://www.turboninjas.com/camry/eg1.pdf

fuel pump relay

Are you sure it's running when cranking? It should have come on when key turned on.
This is for camrys up to year '91. It may apply in your '95, also. Check the 7.5 amp ignition fuse and the 15 amp EFI fuse and the EFI main relay, all located in the fuse box next to your battery. There is also the circuit opening relay tied in to fuel pump operation. It is usually found under center of dash. It is usually not the problem, but it is part of the checks for fuel pump operation.
If your car has a " check connector" or "service connector" (also called a fuel pump check connector) under hood on driver's side near the firewall (a little 1 inch cube with a cap on it), then bridge terminals +B and Fp with a jumper wire. Turn key to on (don't start car). The pump should come on. Listen for fuel return noise from the fuel pressure regulator, and verify pressure in hose from the fuel filter. If nothing, check those fuses above. Here is how power runs to pump: Battery to 40 amp main fusible link-to 15 amp EFI fuse-to EFI main relay-to circuit opening relay-to fuel pump-to ground. Ignition switch and the computer (ECU) work the relays to pass power to pump. Hope this helps some, Randy. Good luck.

this year of car has throttle body injection not a carburetor,the backfiring could be the fuel pump relay not allowing the pump to power up,or a plugged fuel filter,or a bad fuel injector,if their isn`t at least 15lbs fuel pressure the injectors will not open to spray fuel

Check the EFI main relay, the circuit opening relay, and the fuel pump relay. Inside the fuel pump relay there is a switch controlled by a coil. During start, the fuel pump gets full power for a couple of seconds to build up pressure. Once pressure is good, the fuel pump relay is supposed to switch (via the coil) the fuel pump to reduced power. If the coil in the relay is bad, the reduced power setting is not available and the fuel pump will run at full power all the time. At this heavy current draw, it won't be long until the EFI fuse blows. This would also give more pressure than is necessary to the cold start fuel injector which runs on a timer. This extra pressure during the time that the cold start injector is operating may be the reason the engine is flooding with fuel.

Step one
Click the key forward BUT don't start the car listen for fuel pump to pressurize and shut off. But if the pump keeps running change the fuel pump relay switch under drivers seat. If its pressurizing and shuts off then its not your fuel pump. Fuel pressure at rail when idling is 30 psi.
Let me know what happens cause I know alot about Stangs had 2 5.0

Some years of the "F" series pickups had two fuel pumps,, one High Pressure and One Low Pressure.
It could be either one.