2003 Ford Expedition 5.4 EB 200K miles. strong crank with no start. New fuel pump, maybe a ground ?

[David Carelli]

Hello, 03 expi EB 200K miles. Pulled in driveway at night, car runs perfect. In the morning, strong crank with no start. I sprayed starting fluid in throttle body and it starts briefly, so i suspected bad fules pump or fuel pump relay. I jumped the green yellow wire and got no action to fuel pump. So i thought ifound the problem. Bought a new pump and repladed. THAT WAS ALOT OF FUN !!! But didnt fix the problem. I then jumped the inertia switch and that didnt help. I believe now the relay is all that is left. But i am thinking it has to be a ground somewhere, as i jumped the relay and it doesnt engage the NEW fuel pump so i have to have a problem in the grounds somewhere. I can sure use some ideas ! Also, i have been searching the internet for awhile and cannot locate a chart of the grounding locations for a 2003 Expi. Anyone have a chart ? And is there a specific ground that controls the fule pump ?

 

[Yupster Dog]

Start here
https://www.expeditionforum.com/threads/another-fuse-box-replacement.46781/

Welcome to the forum

 

[David Carelli]

Thank you very much for the reply. Question, i ran a 12V jumper directly to the fuel pump Green yellow wire taking the relay out of the picture and the fuel pump still didnt run. And i am getting 12V coming into the green yellow wire. Doesnt this take the fuse box out of the picture as an issue. I also jumped the rear inertia switch. So i am thinking its a ground somewhere. But i cant locate a ground chart anywhere for a 2003 expi. Thanks again for the reply.

 

[BlackCoffee]

It could be a few different causes. Before jumping at the fuel pump, I would put a fuel pressure gauge on the fuel rail and see what you get. 35-50 PSI is the working range. Pressure gauges are cheap and hooking to the Schrader valve is easy. If it cranks, you are getting power to the starter, but there are several other relays that may cause you a problem. I would diagnose the fuel pump first. If you have no pressure, you do not need to start running circuits.

 

[David Carelli]

Thanks for the reply. Did not check the pressure yet because i did not hear the fuel pump coming on, and when i sprayed starting fluid into the throttle body it starts briefly. Also jumped the Green yellow from the relay with 12v still with no start, So i assumed bad fuel pump and just replaced it with a new one. All that work to drop the tank was disheartening when i tried to start it after and would not start. I just bought a new fuse box and will give that a try, but i am assuming it may not work since i jumped the relay out of the picture. I am leaning towards a ground or continuity issue but i cannot locate anything online for a 2003 expi ground locations.

 

[Johnathan M]

Prior to my current Expedition, I had a 2005 with the 5.4 liter. At one point I had fuel issues that drove me nuts as well. I replaced the fuel pump twice (Only pulled the tank once, because the pump didn't run when I plugged it in, so I replaced it before putting the tank back up), thinking I got a defective one. Finally realized I wasn't getting a ground at the pump. So I ran a ground from the frame (drilled a hole in the frame near the tank, and installed a screw to attach the ground) and tied it into the ground wire going to the pump. Problem solved for probably a couple months. One day on my way home it quit on me again. Got it home and started checking things out and now I didn't have power to the pump. I finally figured out that theres a module behind the driver side rear wheel up on top of the frame. It's a square box maybe 3" x 3" x 3/4" thick. I forget what it's called but all the power and ground for the pump run through that box before it goes to the fuel pump. They have a problem corroding internally, especially if the vehicle lives in an area that gets salt on the roads in the winter. What happened was that it had corroded internally enough that the ground was no longer connected, and so when I ran a new ground to the pump, it fixed the problem temporarily. Eventually, it corroded enough that the power supply was also cut off and the pump quit working again. Once I replaced that part, my problem was permanently solved. I suspect that there's a high chance that is your problem. Hope this helps!

 

[Johnathan M]

I believe it's called the Fuel Pump Driver Module. Not sure if your year has it or not, but my 2005 did.

 

[Johnathan M]

If you can't find a ground chart, you could just try tying a new ground into your fuel pump wiring just to see if that makes it run.

 

[David Carelli]

Yes, thanks for the reply. Sounds like a great idea. My inertia fuel shut off switch on a 2003 is in the inside rear quarter panel. I jumped that as well with no luck. I bought a new remanufactured fuse box and will try that first. Then try a new ground.

 

[Johnathan M]

Yes, thanks for the reply. Sounds like a great idea. My inertia fuel shut off switch on a 2003 is in the inside rear quarter panel. I jumped that as well with no luck. I bought a new remanufactured fuse box and will try that first. Then try a new ground.

You're welcome. Just to be clear, I wasn't talking about the inertia fuel switch when I mentioned the location behind the driver side wheel, up on the frame. That's a different component called the fuel pump driver module.