tyguy1

hey everyone im having an issue that no one can seem to figure out :/


My truck is a 2006 f150 5.4 3v fx4


Ive replaced ; Cats Coils Plugs Fuel filter.


My truck seems to drive fine under light throttle but as soon as I go to punch it (w.o.t.) , It gets to about 4000 rpms and the rpms seem to stick there ( ive even wached the fall back 100 - 200 rpms) and you can feel the tuck simply pulling power no shaking or any thing. Its still slowly accelerating when the rpms stick but like I said its slow and you can feel the loss of power. No garages can figure out what is wrong I even took it to the stealer ship and they don't know.


Thanks guys Im going nuts trying to get this truck to run right.

primalurges

The back of the plenum has an actuator that adjusts the flow in the plenum at higher rpms. I don't know what it's called but look up pictures of the plenum and you'll see the square shaped actuator that has two arms connected to each side of the plenum.

lewissa81

It's called the Intake Manifold Runner Control. I think they open up at 3 or 4k rpms. As primal said, that does sound like a viable culprit.

tyguy1

Thanks guys! Ill check it out and ill let you know the outcome . cheers !

tyguy1

Is there any way to test and see if its faulty ? I have access to a diagnostic tool.

tyguy1

Hey guys I tested the imcv by hand and with the diagnostic tool. The Imcv is working fine . could it possibly be a fuel pump issue ? Or which tests on the diagnostic tool would you guys suggest I run? Id hate to get rid of the truck but sadly thats what its coming down to . thanks again guys !

Especial86

iTrader: (1)

You got a CEL light on?
Did you check the cats? Any noise?
Check the intake at the fender for a blockage of leaves and debris?
If you have a diagnostic tool, check the throttle body and TPS sensor (throttle position sensor)

tyguy1

The cats are brand new . Ive got no CEL on and no pending codes. Im gunna make sure there is no blockage
At the fender. As for noises I dont hear anything out of the ordinary. Im going to test the throttle body and tps tomorrow when im back at work and have access to the diagnostic tool. Thanks for the advice man ! Ill let you know what I find !

Especial86

iTrader: (1)

Might as well clean the TB while your at it..
If you've noticed any weird shifting, I'd definitely suspect the TPS..
Might as well check the FPDM for corrosion above the spare tire too..

tyguy1

Thats a good idea im gunna give it a good cleaning . I forgot to mention that I also replaced the FPDM awhile back. But this some soild advice thank you.