So I've been having issues with my late-model 04 SuperCrew with a 5.4 having a rough idle. After searching the forums and reading about the IAC and throttle body cleaning, I figured I would start there. So I take off my throttle body expecting to see an IAC behind it or somewhere near it and there's nothing there.
Am I missing something?

Romer

 

Do you have a new body style F150? Not the older rounded body style truck?

If it is a new body style, then there is no IAC. It has an electronic throttlebody, which has no IAC, because the throttle body does all of the work.

I'd recommend looking at other things like the plugs or the COPS.

 

Thank you for the reply.
It's the newer body style. I got the throttle body all nice and clean.
I've checked for vacuum leaks and other loose stuff, but haven't found anything yet. Since there is no IAC, could it be the throttle position sensor?
It doesn't miss at all which I think would point me away from plugs and coils. It just stumbles a bit and occasionally dies when I'm creeping into the garage.
I just changed the starter since my jobs has me doing about six to 10 trips a day in it.
With 83,000 miles I hope it's not plugs or coils, but I guess the scheduled change for plugs isn't too far off.
I've heard that the new 5.4s are a real pain to change plug due to seizing issues from a factory oversight. Has anyone tried changing them out in their garage yet? I'm sure a dealership will be about $400-$600 if they don't break one off in the block.
Thanks again.

 

I'd suggest removing the PVC vacuum line as it probably has a hole in the rubber curved neck. You'll not be able to see it as it's behind the intake making it necessary to remove it to inspect. It's a common issue on the 5.4. If you replace the PCV valve, use ONLY a Motorcraft unit. If you use a different brand like a Fram, expect idle issues. You can change your own plugs but they're a pain to do. They are a multi-piece design and are known to break off. I'd suggest several tanks of quality brand gas and a bottle of Techron or BG44 in each to clean the carbon deposits out before attempting to break the deposits with the plugs. Look in the Tech Articles here and you'll find a How To for the plugs. Since this is your first time to change them, expect it to take 8 hours. After that, it's a breeze.
https://www.f150online.com/forums/articles-how-tos-119/