Hi there, I recently bought my first F150, it's a 94 short box flareside 5.0l 5spd 4x4. I bought the truck under the understanding that it only needed a fuel pump to run again, so I pulled the box off and replaced the in tank pump. Now the truck turns over starts for maybe 2-5 seconds and stops, I've had a few people tell me that this truck should have the high pressure in-line pump but I've also had several people tell me that this year does not have them. My truck in particular, if it's supposed to have one, does not! I picked up a used in-line pump today, but before I install it I would like to confirm wether or not my particular year should have it. If it doesn't need the pump I've been given a few other possibilities such as ignition module or PCM. Any and all help is appreciated thanks.

 

You need to take fuel pressure read off the fuel rail, to see if it's fuel or spark problem.

 

No high pressure inline pump only the high pressure pump in the tank.
I would have ran a pressure check before replacing the pump but definitely do one like 56 recommended to determine fuel or fire problem.
Pressure should be 35-45psi on a 5.0

By the way welcome to the forum

 

Eliminate the fuel filter as a culprit too. Replace.

 

The pump in tank did need replacing as it did not run at all, and when I replaced it I also replaced the filter. Now when I start the truck, the in tank pump primes the system but when the engine turns over the pump does not kick in again? It doesn't kick back in until the key is just in "key on position"? And thanks guys.

 

It wont come back on until the engine cranks then the ecm turns it back on. Or like you said you cycle the key.
Check pressure and then for spark.

 

You're going to make me think aren't you!

Find your OBD1 test socket.

W/ key on, ground the fuel pump circuit.

This by-passes the PCM relay, as well as the Fuel pump relay.

The PCM relay, I believe is ok, as it is priming the pump for start initially as it should.

I'm betting the fuel pump relay may be pooched, which is supposed to take over at start, after the initial prime.