Stalling issues 03 Expedition

[lightandvideo]

Needing to ask everyone's advice on how to fix an intermittent stalling issue on my 03 Expedition, (XLT, 4.6l, 2wd, 120k miles, engine runs great when no stalls, recent tune-up, new OEM fuel pump, new fuel filter, new exhaust, no error codes, no check engine light)

I did a bunch of research, and looks like this stalling is a common and difficult issue to diagnose, and saw lots of different advice on potential issues that will cause intermittent stalls,

Has been stalling occasionally for the past couple years, sometimes no stalls for several months, sometimes it stalls 2-3 times on a short drive, and usually starts back up immediately.

Stalled twice yesterday on a short drive, while driving 35-45mph, and wouldn't start up again for several minutes, (blocked heavy traffic in a busy intersection, so I need to figure this out and fix the problem asap before I can drive it again!)

It has stalled at freeway speed, and it has stalled when slowing down or idling at red lights, basically it happens unpredictably and acts like it is out of gas and engine just dies.

When I stop the truck, turn off the ignition, and restart, normally it will restart immediately after a couple tries, (but not yesterday!)

Sometimes the engine sputters slightly before dying, when I feel it lose power while I am driving sometimes I can pump the gas petal and sometimes the engine revs up and keeps going, sometimes it sputters and dies, sometimes it just dies, very unpredictable but it always acts like the fuel pump is not getting gas to the engine...

When it starts back up, the engine always runs great, there is no check engine light, and my mechanic (he is a very knowledgable retired Ford factory mechanic) can't get any error codes to help us figure out what the heck is going on!

I already spent the money to replace the fuel pump, and I had a new factory OEM fuel pump installed a couple months ago, but the truck stalled out again within a few days of replacing the fuel pump. (My mechanic tested the old fuel pump before replacing it, and the old fuel pump was performing on the bottom-end of factory spec, so I don't feel too bad about replacing this, but would have been better if this expensive repair solved my stalling problem!)

My mechanic then told me to watch for stalls if the gas was above 3/4 full, or below 1/4 full, and he said if the truck only stalls when full/empty this might be a problem with the evap system,

(The truck seemed to stall only when the gas tank was either completely full, or almost empty, but yesterday the truck stalled with exactly 1/2 tank of gas...)

At this point I think it might be the fuse box & integrated fuel pump relay, and have no idea if this might be some issue with the evap system, but I can't find any posts online about evap system issues causing intermittent stalling issues,

I went along for the past few weeks keeping the gas over 1/4 and below 3/4 full, and didn't have any issues until yesterday when the truck stalled twice and wouldn't restart for see real minutes with 1/2 full tank, so I am guessing this is not the evap system issue, also because there are no error codes or check engine light it seems like this is unlikely that the evap system is bad, is this correct?

I have seen several posts and YouTube videos suggesting replacing the entire fuse box (with the integrated fuel pump relay soldered to the board, and not replaceable), and it seems like this is probably the next thing to try?

Has anyone else worked through this same nightmare?

Am I wasting money buying a new fuse box with integrated fuel pump relay?

Any other suggestions?

Thanks in advance for your help figuring this out, Any advice or experience you can share is greatly appreciated!

 

[stilbo]

I dislike guessing games but....

Have you tried cycling the inertia fuel pump shut off switch several times?

 

[Hamfisted]

Are you the original owner ? You can pull that top right relay in the fusebox (PCM relay...), and see if you see any signs of melting around the terminals on either the fusebox or the relay itself. All three of those top relays are interchangeable in a pinch. So you can swap one around and see if conditions change. Generally when the fuelpump micro relay goes you'll hear a buzzing coming from the fusebox. Check the chassis grounding cable from the battery to the chassis, make sure it's not corroded and tight. Good charge going to the battery too. Ever any DTC codes ?


-Mike

 

[lightandvideo]

Thanks for your replies, my mechanic told me he tested and changed all of the serviceable relays on the fuse box, but I saw several posts on YouTube etc that the actual fuel pump relay in soldered directly to the circuit board in the fuse box, here's a link to the video I saw on YouTube:
https://youtu.be/JjnlWO4ciFg

 

[lightandvideo]

Thanks for your suggestion Stilbo, how do I cycle the inertia fuel pump shut off switch? Is this easy to do?

 

[lightandvideo]

I haven't tried pulling the fuse box to check the circuit board, but the symptoms on the YouTube video sound almost identical to what I am experiencing, after seeing this video I was almost ready to just go ahead and order a new fuse box, but not 100% sure if this is the problem, and didn't want to waste time and money if someone has any other suggestions, (I guess I need to pull the box and see if there is damage to the board and integrated relay) Any other ideas?

 

[Habbibie]

What you have is a fuel delivery problem, same thing was happening to my friends explorer with 4.6L, he replaced the fuel pump but the problem persisted, I helped him remove the recently new pump and swap it for another new one (warranty swap) then I also replaced his fuel filter and finally I cleaned his injectors the correct way by tapping into the fuel rails and shooting concentrated injector cleaner directly to his injectors without mixing it with gasoline. (If you don't have the tool for this Jiffy lube does it for 40-50 and takes about 30mins)

Anyways after I did that for his truck the problem never returned and this talk is a few years ago....he still has the truck and to my knowledge it hasn't stalled since.

When you say sometimes you can't turn the truck back on right away that's a red flag for fuel pump failure.

 

[Hamfisted]

The fuel pump micro relay is good for 100-120k miles. If your Expy is in or over that range a new fusebox is probably a good idea. There are relay repair services on Ebay if you want to go that route to save some money. I haven't seen any reviews on their work good or bad. Supposedly the new replacement fusebox is redesigned with a heavier duty micro relay but I'm not an electrical expert so I can't swear to it.


-Mike


2003-Ford-Expedition-Fuse-Central-Junction-Box-new-3l1z-14a068-aa-a11

 

[lightandvideo]

Thanks Mike! Yes I went ahead and ordered a new factory OEM fuse box and decided to handle the install myself to save on labor, (I paid around $375 online, includes pre-loaded new fuses and relays) I did see several vendors offering repair service for the original 2003 fuse box, but apparently they are now shipping a newer generation version with different part number, but is fully compatible with the original 2003 version (but without the design flaws that led to common issues on the original 2003 units) New box is due to arrive on 6/1, hopefully this does the trick for another 120k+ miles!

 

[Bedrck47]

One thing you should consider doing is to pull and clean the throttle body The exhaust ports that go thru the TB tend to clog up and the 4.6 engine will clog much worse that the 5.4

Check on youtube for the following video

P0401 code ford Throttle body EGR port cleaning 4.6 Ford Expedition part 2 of 5

You may not have the code but this is something that needs to be looked at

also some more information for you
http://www.expeditionforum.com/f42/about-egr-pcv-dpff-evap-iat-tps-maf-23583/#post191356

 

[lightandvideo]

Update, I received the new fuse box last week and had no problem installing it. So far zero stalls with the new fuse box, I will post another update if stalling continues, but I think we finally solved the mystery!