bluescrew

I've utilized the search function but for the life of me I am unable to dig up any information on a problem I am having.

Recently when I start my truck up after work (doesn't do it in the mornings) it goes to its normal high idle of 1400 rpm. Then after a few seconds it shoots up to 1800-1900 rms for ten seconds or so then it drops back to 1400 for a few more before finally landing at 900-1000 rpm. I'm thinking it is a high idle switch/solenoid but I had no idea where it is located or what all is involved with replacing it. I remember with my old carbed truck it took more time to get the air cleaner off than it did to replace it. Anyways, it just started happening this week and I thought I would ask here before I hap-hazardly start replacing things. It's an 04 with the 5.4. Any thoughts and suggestions are much appreciated.

~Bluescrew

bluescrew

Hate to bump myself but some additional information:

62000 miles
Bone stock
Fresh air filter
fresh fuel filter

Thanks!

bobkyle2

i would says its your idle air control valve... i dont know much about these 5.4s but it sounds like your problem

jeffreymd2

I have not had that problem on my 05 fx4. I just recently had that problem with my eclipse. I checked the IAC valve which was fine then a mechanic told me to check the coolant He said if it was low it would cause a high idle when. I ended having a crack in my overflow tank. That was a lot cheaper then the IAC valve. Hope this helps.

clignat

Negative on the iac valve 04 and newer ford pickup. Electric motor controls throttle and idle, no cable, computer controlled, check for vaccuum line disconnected. Some f150's were proned to start up idle flare, programming with the latest version was the fix. We live in acomputer world!