Hey guys


My heavily used '05 F150 (107,000 miles) just started cutting out at heavy or full throttle applications. Like when i need to pass somebody

The gas mileage seems stable (15 or 16 mpg - same as always) and there are no lights on in the dash ---- so i did not think it was the coil packs, plugs or O2 sensors. The first thing i did was change the fuel filter --this did nothing.

Could it be the fuel pump? or something else i haven't even thought of yet --- i was under the impression that when fuel pumps go, its like a light switch though, on or off.

The truck runs fine when its cold -- this condition usually starts in after about 30 minutes of use


With the mileage i have on it, i realize its a good idea to change the plugs, but if its not backfiring or getting bad mileage, i didnt think they were the primary cause of this weird deal

Thanks for any input. Hopefully you guys can help keep me from buying $500 in unnecessary parts trying to "fix" this

 

Sounds like the 05 injector problem. Unfortunately you may be out of luck as Ford extended the warranty to 11yrs or 100,000miles. Check out this thread.

https://www.f150online.com/forums/sh...light=injector

 

The other thing you may want to check is the fuel pressure at the fuel rail. Go pick up a guage, and connect it to the schrader valve on the fuel rail.

 

Thanks for the tip and the link, BubbaJoe. Most of those guys in the thread were getting it taken care of under warranty, but since i'm 7k out of warranty, i feel a little more helpless. Its a cold feeling looking under the hood of a modern truck with little more than a droplight and a pocket full of wrenches

Are the injectors expensive? Dumb question, i know -- but its Sunday, and i wont be able to get a price for a while. Access to replace them looks better than the spark plugs.

The fuel rail test won't be ble to isolate which specific injector(s) it is, and i dont know if i will be able to test them with my rather typical home garage setup

 

If you have 107k on the original plugs, you are overdue for a change. If you have a 5.4, good luck. Misfires under load will not necessarily trip a CEL. You may need both plugs and COP's.

 

I relize this, but aren't those problems usually accompanied by a significant increase in fuel consumption ?

 

I know the Schrader on the previous F150, but were do you find one at the 2004 and up?

 

Not necessarily, the O2's are adjusting the overall mixture - and you are running the cylinders that are not misfiring excessively lean now, which can burn the valves.

 

[QUOTE=bubbajoe28]Sounds like the 05 injector problem. Unfortunately you may be out of luck as Ford extended the warranty to 11yrs or 100,000miles. Check out this thread.


Hay Bubbajoe and Streetstar, my letter from ford says "11 years or 120,000 miles from warranty start date". Streetstar if your not the original owner run your vin # and go to your local dealer tomorrow. Good luck and please post your outcome concerning this situation.

 

[QUOTE=clambelly]Clambelly,

You are correct!! Just found a copy of the letter. See below.

https://www.f150online.com/forums/sh...d.php?t=312997

 

Streetstar,

The injectors are about $40 a piece. They are alot easier to change than the plugs. Pick up a Haynes repair manual for $10. The whole procedure is in there. Should be a couple hours work on a Sunday. Check with your dealer first as the warranty is actually 11yrs or 120K.

 

Autobahn,

Just looking at my shop manual. You actually need a T-fitting for the 04+ F-150. You T into the supply prior to the fuel rail. The manual states a 30-40psi at idle, and hold pressure of <5% decrease after 5 mins.

 

The dealer is going to laugh at you if you go in there with 107k on the factory plugs complaining about a miss when you ask them to do warranty service on your injectors. If you have a 5.4, better pay them to change the plugs - and before you start, ask who pays if the plugs break.

 

I have the same problem.... Im pretty sure its the fuel pump. My pressure drops to 3psi when the problem starts... Im gonna make a video and post it tomorrow night. I also just changed the fuel filter 4 hours ago... No help there but worth a shot

 

3psi at idle??? The manual calls for 30-40psi at idle. 5 mins after you turn it off, the pressure should not drop more than 5psi. If you get good pressure at the fuel rail, you can rule out any leaks in the lines.