OK

This question is for those of you who live in cold climates (10 degrees and below). My F150 starts fine, even when it is -10. The problem is, when the outside temp is below about 5 degrees, the engine starts and dies right away. If I keep my foot on the gas and "feather" the gas pedal for a few seconds and the let off, the engine runs and idles just fine.

Any clue as to what may be causing this anomolous behavior?

Thanks.

 

Jag,

Clean the IAC valve.

JMC

 

I have the same problem, but I didn't have it when the truck was new. It has 37,000 miles on it now and last weekend when it was -20 the truck did exactly what Jag described. Unfortunately I was visited relatives, so my truck wasn't sitting in the garage, so it doesn't normally see this temperature.

JMC,
Please help, where is the IAC valve and how do you clean it?

 

You can clean it with brake parts cleaner.......just anything to get the "gunk" out of it.
It should be on the side of the upper intake.

--Joe

 

Thanks.

I'll try cleaning the IAC valve.

BTW "soap", cool truck.

 

Thanks for the kind words........

There is a picture of what you should be looking for in this thread.

--Joe

 

Jag, have you tried cleaning the IAC valve yet? This is very similar to a to a problem I have had recently. I thought my problem was due to some high water I went through. JMC had suggested I check a few things and the problem seems to have been corrected. We do not have that many cold mornings in Southern Texas, but that seems to have been the only time the problem would manifest itself. I will clean my IAC anyway, but I am just curious to know if it solved your problem.
Rick

 

As I mentioned in that thread, the Lightning guys have got it pretty good on the location of the IAC. It looks the same on the 5.4L NA and 4.6L but it's actually farther back and alot harder to get to.
Mine is approximitely under the passengerside windshield wiper post.

 

Excuse me for being somewhat uninformed about many of the acronyms used but what does IAC stand for and what does it do exactly. I cleaned mine today at lunch because my truck has been behaving exactly as the descriptions state. I attributed it to the winter blend gas though. I will say that after some cleaning with break cleaner the plunger seemed to move much more freely. We may have some more cold mornings to see if I have made a difference. Thanks for the additional info.

Dave

 

BERVINATOR,

IAC stands for Idle Air Control. It is a valve that allows air to bypass the closed butterfly valve in the Throttle Body. When these trucks are at idle the butterfly valve is completely closed. Some models have a hole in the butterfly but not enough air can get by to allow the engine to idle. The IAC allows air to go around and feed the engine. It is controlled by the PCM (Powertrain Control Module). The PCM is the computer that controls the engine. Hope this helps.


Jean Marc Chartier

 

I cleaned my IAC and also cleaned the MAF and the intake air temperature sensor. It starts much better in the cold - it was -9F this morning and it started good - I hope that this cheap fix is all it needed.