New to the forum, I have a 2000 F150 that has me confused. It will start fine for a few days than nothing. I wiggle the harness going into the fuel pump and it fires right up. Any ideas?
Thanks

 

Define "nothing". I bet SOMETHING is happening. Dash light up? Engine crank? You didn't give nearly enough info for anyone to help.

 

Sorry, it cranks over, by nothing, the fuel pump does not get power until I wiggle the wire. It only does it while parked and shut off. I can drive for an hour or go through a corn field and nothing happens.

 

What wire are you referring to? At the tank? From the PCM? From the relay? How do you confirm the pump isn't getting power?

 

The small harness going into the fuel pump at the tank. You can not hear the pump kick on when it acts up. I haven't tested voltage yet, tomorrow's project. Hoping not to lift the bed or drop the tank. Ford dealer put new tank straps on a few months ago and I had them check it. They didn't "find" a problem. Of course it didn't act up then. Sorry, not the best and defining stuff while typing. I would think it would act up while driving, hitting bumps and such, not after parking it.
Thanks

 

Hmmmm. That doesn't make sense. I'd agree that it should happen on bumps too.

 

Is there a small harness from a relay attached to the frame to the pump that could have a short in it? I don't think it is the pump itself or the "wiggle" the wire wouldn't cause it to fire back up! It is really strange. With winter around the corner where I'm at, my other vehicle doesn't cut it...

 

This is the harness I am referring to. Sorry for the pic quality, it's from chiltons

 

There is a relay under the hood which is hot when the key is on and grounded by the PCM. There is also an inertia switch, but no other relay to that harness.

I'm still a bit confused though... So you turn the key and the engine cranks, but doesn't start. You go back and wiggle the wire and then you hear the fuel pump run? The fuel pump should only be energized for about 3 seconds without the PCM detecting that the engine is spinning from the cam and crank position sensors. If yours runs any time the key is on, someone modified it.

 

correct, when it starts I can hear the pump "energize", when it doesn't, I do not hear, wiggle the said wire and fires right up. Lights, dash everything works just doesn't start. Wiggle the wire and all seams good. Like said, confused why it doesn't do it and die driving down the road, only after it sit for awhile. I do not hear while it is running, just startup like you said, maybe 1 or 2 seconds

 

Sorry man, I've got nothing else for you. Dropping the tank isn't too bad on these trucks though.

 

Shouldn't be bad after the dealer put new straps on it, other the fact I 3/4 tank of gas in it
Thanks shoot for helping

 

I suspect the harness has an intermittent break or short in it. Once the engine is running, there's probably enough residual pressure in the fuel system to keep it running even if the fuel pump loses power for a few seconds. That might explain why you don't notice it while driving over bumps. Just a guess. Looking at videos posted online, you may be able to disconnect the harness without completely dropping the tank. Good luck.

My fuel pump died yesterday, 5 minutes after filling up with 26 gallons (190lbs!). :/