Guys,

I have a 5.4L that at times after running for a while doesn't want to restart, but is not consistant. I am thinking it is a fuel pump, but before I shell $270 I want to verify it.
After driving it if I go to restart is the engine turns over, but sounds like there is no fuel getting to the engine. The relay under the hood sounds (clicks) like it is working, but no sound from the fuel pump. Are there any other items (other than wires) between the relay and the pump or is the pump the problem? Any help would be greatly appreciated.

 

Since you didn't identify your vehicle, the following is based on the 97 pump circuit. If you have a differnt year, the circuit might be different.

Always hot via F19 (underhood fuse box) to fuel pump relay normally open contacts. When relay is energized by the PCM, power is sent to the inertia cutoff switch, then to the fuel pump.

Personally, I'd test at the switch to see if power is being delivered to the pump when it fails to operate.

Steve

 

Try to push the gas pedal about 1/4 way down the next time it acts up. If it starts, it could have a bad IAC. If that doesn't work, try smacking the bottom of the gas tank with a 2x4. Sometimes this will unstick a stuck pump. If that works, then replace the pump before it leaves you stranded.

 

It is a 1999 F-150 5.4.


Thanks for the input, I was not sure if the cut off switch was before or after the relay.

Cope

 

Thanks for the replies. If all else fails, just to continue wacking on the pump with the 2x4 will at least relieve some frustrations.

 

Yep, I have started many of them this way. It makes it easier to pump the gas out of the tank so it isn't so heavy when dropping it to change it out.

 

i was wondering if you were ever able to fix or find out what this problem was????? this is the 2nd time this stalling has happened to me and luckly i was at home when the stalling occured! it's strange though......trucks drives fine and starts fine and then all of a sudden you stop the car go in for a beer come out to the truck and it doesnt carry an idle.

it cranks, catches idle for 1 sec, and then dies. i have a 2000 f250 5.4L.

thank you

 

Sounds like the pump has a bad spot in the winding and every now and then when you turn it off, it stops in the bad spot. Sometimes a jolt from a 2x4 will move it enough to start up again.

 

i found out it was a bad winding in the fuel pump. we replaced the fuel pump and everything worked fine. we knew it was a bad fuel pump when we put a ohm meter on it and there was no resistance in the pump motor. problem solved due to poor manufacturing of a fuel pump and ford's cheap pocket books to not ensure quality. 20,000miles on a truck and a shot fuel pump . thanks a bunch for your help!!!!