OldFordTruck

I ended up inheriting a 4.9L 1990 F150 that has sat for a good 3 years. I got it running fuel pump relay was bad. But I notice when I turn the key to start it the fuel pump never shuts off. The truck though starts and idles fine. I have not driven it yet as it still needs to be inspected. I also pulled codes from it and got KOEO 95 Fuel pump secondary circuit failure-PCM to ground. So if it starts and idles fine where would I start looking to fix this condition?

Chris_1

iTrader: (1)

Pump is supposed to come on for about 2 seconds and stop. Then once it starts, if - and only if, the motor is running the pump should come on and stay on. That is computer controlled.
The 2 seconds is primary circuit and constant run is secondary circuit (I believe).
I would guess that maybe the PCM isn't grounded properly or it isn't grounding that circuit properly internally.
I believe that most of those circuits provide power to the controlled unit and back to the computer which completes the circuit by grounding it.
Of course if somebody grounded the pump somewhere else (that they shouldn't have) then the pump would run constantly.
That's all I've got for ideas. Couple things to look at though.

OldFordTruck

I swapped my fuel pump and eec relay's as they where the same. Turns out it fixed the problem. Fuel pump primed and shut off. Start the truck then shut it off but it wouldn't I had to pull the swapped relay. So turned out the new relay I bought was sticking when it is being powered. Also was cleaning out the glove box and found a fuel pump and eec relay my father had. Put the fuel pump one in and now it works fine.

Pwaho

Good fix and thanks for getting back to us with what you found.

OldFordTruck

Another thing. At least I didn't pay full price for the relay either. There was a bunch of discounts happening at the time so I got it for about half off.