Recently bought '99 F-250 SuperDuty with Triton V-8. Has been starting and running great until last week when cool weather (45 degrees) moved in. Twice now, engine will not run when engine is cold and it's cold outside. I can keep the engine running by keeping the accelerator depressed but it will die once you remove pressure. By keeping my foot on the accelerator for several minutes and warming the engine, the truck will eventually maintain an idle and it will run fine. Any ideas on this one? Could the idle air control valve be sticking or could this be a problem with the TSP?

 

I am having the same problem with a 1999 f-150 5.4L. Spray some carb cleaner into the intake the problem would go away for a week. Bought a new IAC valve ($60 from Ford, after market valves are not available) Removed the old one today and found it had a different part number. Might have something to do with engine calibrations. I cleaned the old valve and reinstalled it. (The shop manual says to replace and not clean) So far today so good. I need to get back to the dealer Monday to figure out the correct part number. When I bought the replacement valve the dealer did stay it would not be covered by the emissions system warranty. I'll let you know what I find out.

 

Thanks for the info. I'll let you know what I find out tomorrow as well. I finally drove the truck to the Ford dealer this afternoon. I talked to an independent mechanic who thought it was the intake air temperature sensor that was bad. I pulled it and ran a resistance check on it and it was pretty much out of specs. However, again this is a dealer item. I also considered pulling the idle air control valve, but that valve sits on the back side of the throttle body which sits pretty deep under the cowling on the F-250's. It was hard enough just being able to reach back there much less trying to remove that thing. This may not be covered under my extended warranty, but I'm hoping it'll be less expensive than me spending my time and money swapping out expensive parts. I've done that.

[This message has been edited by Russty (edited 10-08-2000).]

 

Thanks for the info. I'll let you know what I find out tomorrow as well. I finally drove the truck to the Ford dealer this afternoon. I talked to an independent mechanic who thought it was the intake air temperature sensor that was bad. I pulled it and ran a resistance check on it and it was pretty much out of specs. However, again this is a dealer item. I also considered pulling the idle air control valve, but that valve sits on the back side of the throttle body which sits pretty deep under the cowling on the F-250's. It was hard enough just being able to reach back there much less trying to remove that thing. This may not be covered under my extended warranty, but I'm hoping it'll be less expensive than me speding my time and money swapping out parts.