Greetings, I am a new member to the forum and I have a problem that hopefully one of you folks can solve. I have a F150, 5.4L, Auto, 4WD. Truck runs fine but will not idle, happened suddenly, drove it to work today with no problems started it to run for coffee and it hasn't wanted to idle since, had to drive home with foot on brake (slowing/stopping) and foot on gas pedal to keep it from stalling. No check engine or fault lights. Any help would be apreciated.
Thanks, HDFXST

 

Need new Iac valve or tps.

 

Your IAC is fouled.
It is sticking.
To verify that this is the problem, tap it and it will unstick and the truck will idle.

If this happens away from home you can use your jack handle.
If you don't know where the IAC is, use the search feature (IAC*)
this is a common problem and has hundreds of posts about it over the past five years.

 

Pulled the IAC valve this morning and cleaned it out. Good as new, thamks for the help.

 

I just went through the same thing. Others here have said that cleaning it might be only a temporary fix (as in months).

When you do decide to replace it, be sure not to go to the dealer as I did for $132 (tax included). Someone on this site mentioned o'reily auto parts and they had a borg warner IAC for only $44 (of course mine being a 4.6L 5-speed might of had something to do with the higher price since that's not the most popular combination, I don't know)

cbone