Hi, I'm new at this, please bear w/ me... I have a 2001 King Ranch..5.4, last for about a month now...off and on...while driving...my baby starts idling really rough. ( without the ac on.) I got in my truck last night to leave work, started it, she did a full start, and shut off.... 3 or 4 times in a row she did this...could not keep her running. Finally she started, I went about 3.5 miles to pick up my kids, did't think, just shut her off, but she did fine starting back up.
This a.m. she did that whole could't keep running thing again for about 6 minutes....finally, I gingerly held the gas and brake and got her running ...kids to school, 7 eleven and then work, trying to konk out all the way...
3 hours later, had to run an errand for work....she started right up, sounded like my strong, tough baby.....no problems!!!!
I was raised by a mechanic and divorced one....I'm not the average female either.However, I know next to nothing about fuel injection....and electronic crap....but in the old days, I would say I had a clogged jet or trash in the carb.......Could this be something as dazzlingly expensive as a idle air control valve?....maybe just a vacuum leak in general???
Please send help!!!

 

Sounds too intermitent to be a vaccuum leak, has the fuel filter been changed? Also, may be a sensor or an injector problem.

 

That would be the first place I looked, even if it has been changed. If you got a bad tank of gas on accident it can easily clog it up. Sounds like it's doing the same thing mine did when my fuel filter plugged up.

 

Second to that! and check if there's some leaks. BTW, Welcome to the CLUB.

 

I think it's your IAC(Idle Air Control).

This is a common problem with all EFI engines. Usually just removing it(it's the 'tomato paste' looking shiny 'can' somewhere on the passenger's side of the intake(I have a Lightning and it's on the rt side of the plenum). Remove the two bolts(10 mm) and the elctronic plug. Rinse it thoroughly with brake cleaner, shaking it too to get the carbon out of it. A Q-tip will help. Reuse the gasket and tighten it evenly back on.

Too much carbon in there will hold the valve off of its seat a tad, allowing too much air to go thru it and you idle rpms will 'search' and the engine's rpms usually die at some point.

Welcome to F150 .


Dan

 

I second the IAC Valve. Sounds like my Explorer a while back. If it was my I would just go buy a new one. I think it was like $30.