Hey all long time listener love the show!

I am a member here but it is in the 73-79 area and occasionally peruse the 7.3 side.
I have been reading and searching and reading about the all too popular stumbling 5.4 because I am now the owner of one as of yesterday for no known reason.
The wife drives a 2006 Eddie B auto, 2wd, yada yada yada. Its showing 83k on the clock and the following has been done; New plugs,coils,air filter, and trans fluid change at 60k along with the normal routine maint. Now the next mentioned item was neglected by me cuase it slipped my mind, the fuel filter, I changed it this am due to the stumbling. That did not solve the problem so I did some reading here at lunch and it was mentioned that the mass air flow could be a culprit. Not true hope this saves someone $115.00. I have removed and cleaned the throttle body and that seemed to help a LITTLE, it was filthy but did not solve the problem either.
Now I can drive this pig by manually shifting from low to mid to drive and it will never skip a beat shifts right on up even reaching higher than 3k between I mention the 3k cause if it is in just "D" and shifting it never see's 3 and boggs down apon acceleration and I can continue to press the gas pedal with no change. As a side note while in park or neutral I can rev the engine right on up to 3k and it is smooth as silk then will back down to 2,800 and pulsate but put it in gear and it is gutless.\
First couple of thoughts were bad gas but the tank was filled up last Monday and burned down to a 1/4 as of right now. So I would say no, but I will say what came out of the filter was brown and dirty in fact a little gritty? So this leads me to ask if anyone has solved the mystery yet and could it possibly be a failing fuel pump?
Forgot to mention that I have hooked up the OBD II and do not have one single code.
Overdrive on or off does not seem to make a difference either.

 

You could be right about the fuel pump, the first sign of a failing pump is loss of power under a load. Start by doing a fuel pressure test.

 

thank you for responding alloro I have seen you respond several times on other posts and was hoping to hear from you on this one. Wont be able to do that test until Tuesday I close my shops down on the fourth. Gotta take care of those who take care of you!!!!!!


Anyone else???????

 

Our 2003 5.4l XLT was first losing power above 3k, especially when going up hills.
I had changed the COPs, fuel filter, air filter, run injector cleaner, cleaned the MAF, tried another MAF and checked all the vacuum hoses. The RPMs would rev up to 4k in neutral, but had no power under load above 3k and slowly got worse. Get a fuel pressure gauge and check the pressure at 3k, should be around 50-55 psi. Check the vacuum at 3k, should be around 10-12 inches, if it's around 2-4 psi you may have a clogged exhaust. Ours had clogged cats. Replaced the cats and it's running like new.

 

Thanks R&T
How many miles were on yours, this thing only has 83k and that seems to be premature. With this sorry stuff they call gas though maybe they are clogged.
Where did you pull vac from? Pic would be great.

 

Do you have the ability to data log the truck and see what the computer is seeing?

 

Ours has 128k.
Put a T in the brake booster hose and duct taped the gauge to a wiper while I drove it.
I've read the factory warranty is 8 years/ 80k miles, hmmm.

 

This piece of Ford from the stealership was 3 years 36k miles. Or are you saying something not well known about the exhaust system?

 

No, I don't know that there's anything inherently wrong the exhaust.
Actually we have a '92 Explorer with 216k and it still has the original cat.
The Expy had a ticking noise just behind the right pre-cat for months before the clogging got really bad and then the ticking went away.
A piece of something may have broken off inside.
I've haven't cut it open to find out what is was, yet.

 

ironhand, not sure how i missed your post but are you refering to hooking up a laptop? I have one not aware of how to. Tell me what I need and if its easy enough I'll give it a shot cause I really dont want the stealership reaming me.