UPDATE: 03 Ford Expedition 5.4L won't accelerate

[blue oval guy]

Fuel pump or throttle body issue possibly. 1st things first need accurate fuel press reading @ the fuel rail.

 

[theoldwizard1]

You may also want to try cleaning your throttle body, that can cause surging and rough running idle conditions.

I am a retired Ford Powertrain engineer. That procedure is a waste of time and money. It the throttle plates moves and the Idle Speed Actuator is working properly (which it sounds like it is not), then that service is COMPLETE UNNECESSARY !

What appears to be harden "gunk" inside the throttle was actually placed there on purpose when the throttle body was assembled.

 

[theoldwizard1]

My 2000 Expedition makes no such noise.

Yes, it does you just can not always hear it in side the vehicle.

Have someone else sit in the driver seat. Remove the gas cap and bend down close to it. Have the second person turn the key to ON (not START).

Every single fuel inject gasoline vehicle I have EVER seen turns the fuel pump on as soon as the key is turned to ON. The fuel pump stays running for 2-10 seconds even if te engine is not running.

 

[theoldwizard1]

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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This get my vote ! A large vacuum leak will cause poor running and the IAC can not compensate for it cause the IAC code.

That picture has me confused. I can't tell what I am looking at or what the part is you are describing.

 

[waldo]

This one is better



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[theoldwizard1]

I'm sorry I still have not figured that hose out ! You said it goes from the throttle body, but where to ? The power brake booster ?

 

[MrBlargMan]

Check that fuel pressure. Anything under 55PSI is a no-go.

 

[waldo]

Passenger side valve cover


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[SEPTIC PROFESSOR]

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

 

[waldo]

2L3Z-6A664-B

That part should fit both 4.6 and 5.4 second gen expeditions


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