UPDATE: 03 Ford Expedition 5.4L won't accelerate

[BRIANGEE]

This is where people have to put their learning disabilities aside and re-read the posts... the IAC was changed out. The MAF was changed out. Throttle body will not be so bad as to make it die after one minute of idle. Fuel injectors to the bottom of the list, CAT to the bottom of the list.

I know people want to be helpful but some people's idea of helpful is to tell her to check her windshield wiper fluid.

 

[ringding]

There is a vacuum leak most likely. Probably around the parts that were changed out. Makes the most sense since your condition is now worse.

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[zombiesweets21]

first, just sit in the truck, windows down. Turn the key to the on position (don't start the vehicle). You will hear a distinct high pitch sounds for two seconds.

If you don't know what a fuel pump sounds like now you do.

Now start the vehicle and listen for that sound. It should stay constantly high pitched - not for two seconds anymore but all the time. You may not be able to hear it over the engine so if you can't distinguish the sounds you may have to get closer to the fuel pump - go to the gas hatch area, open the cap if need be and try to hear the pump and if the pitch changes just before the vehicle dies.

If the vehicle dies consistently after a minute or so this should be an easy and free test - if you hear the pump noise start to become erratic, change pitch or whatever then the vehicle dies that will ate least point you in the right direction. It doesn't mean the pump is bad necessarily but it does mean you're on the right track. Really you need a fuel pressure test kit... but this will work for now.

Okay I did just like you said and heard the pump with the key in the On position. But I couldn’t hear it over the engine when I started the car. It stayed on a bit longer this time, but kept shaking then shut off illuminating all dashboard lights.

 

[Clemson82]

Okay I did just like you said and heard the pump with the key in the On position. But I couldn’t hear it over the engine when I started the car. It stayed on a bit longer this time, but kept shaking then shut off illuminating all dashboard lights.

You mentioned it's been sitting, put some dry gas in the tank.

 

[BRIANGEE]

Did you open the gas cap and listen there as well? The engine might be too loud but all these are just small things that anyone can do without specialized knowledge, tools, and don't take much time. It's not the ideal test but without the proper test equipment or scanner options are limited. What you really need to do is get your hands on a fuel pressure test kit - it's a really quick test.

But like others have said, if this started after the IAC was replaced then unplug it and examine the connectors and make sure they weren't damaged. It could be a vacuum leak as well... could be a lot of things. If you want to continue down the path of fuel delivery then fuel pressure test kit, or spray carb cleaner down the intake without hitting the MAF sensor ( I would check for an easy place to do this on mine right now but it's not here at the moment.) What you would want to do is spray a few spurts of carb cleaner or whatever and see if you can keep the truck alive when it starts to die. If you can then you know it's a fuel delivery issue. If it doesn't make any difference then it's probably a vacuum leak or something else...

 

[waldo]

Check this:
On the back side of the elbow that goes down from the throttle body there’s a rubber fitting with a hose that over time gets soft and either leaks or collapses.

Had all the same symptoms and finally figured out it was that.
$12 part

I’d would check there before spending any more money.




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[SEPTIC PROFESSOR]

Excellent photo and tremendously useful information. Would you please share the part number? Thanks in advance.

 

[plumcolr]

Had the same problem. It was in my case the PCV line not being firmly seated where it enters the intake manifold. It would start, run like crap for a few seconds then die. I re-seated it. Make sure to hold the tab lock all the way open, push firmly in place before releasing the tab lock.

If it's the other end of the pcv line, it would probably keep running, though like crap.

 

[Trainmaster]

Waldo's problem is what I suspected, reading your posts. It could be a massive vacuum leak, which would be a deteriorated leaking or unattached vacuum hose. But once again, Moose says it all. You need a mechanic. They guy you got on "yourmechanic.com" is a hack or a thief. I strongly doubt too many reputable and knowledgeable guys are doing service calls for yourmechanic.com. Real mechanics don't ride around in noisy Hondas selling brake fluid flushes in your driveway.

Since you mention that you're no car wizard, go find someone who is. A problem this obvious shouldn't be too difficult to diagnose for a good guy. Sometimes, Internet forum guesses just aren't enough.

And frankly, no amount of dirty steering fluid, dirty air intake or gas less than three years old would make a car run this way. Steer clear of the nonsense and get someone who can find the problem. In the meantime, look for a disconnected or messed up vacuum hose (generally under a three-quarters of an inch) and possibly listen for a sucking sound where the hose is leaking. The lean bank codes point toward this kind of problem, along with the fact that the problem started quickly.

"yourmechanic.com" ought to be ashamed.

 

[waldo]

Here the annoying thing with that little elbow. If it has a hole the car will turn off at idle. If it’s rotted but no hole when you accelerate it collapses shut and the truck won’t go. I don’t have the part number but the dealer will know exactly what that is.


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