RECAP - 2000 Expeditiion, 4.6L

6 mos ago, vehicle would stall on way home from work (still in parking lot) when foot removed from gas to step on brake. No pattern, not able to duplicate - added gas additive, went away....

3 mos ago, same thing, no gas additive used, went away - still no pattern

Last Monday, in afternoon after work, stalled again in parking lot when removed foot from gas. Yesterday, same thing.

ONLY pattern I can now determine is that after a weekend (truck sits for two days), then I drive to work no problem. When I go to leave for home, problem arises.

Anyone else ever experience something like this? Any recommended solutions??

Thanks.

 

Simple explanation, IAC valve.

It is a little round metal part attached to the backside of the throttle body. A new valve costs around $65 at Ford and can be installed in about 15 minutes. Very common problem with these engines.

 

Thanks Buzzard

 

As a side note, what does this IAC do? Is this just a coincidence that it happens after the vehicle sits? or is it worn or what??

Thanks again.

 

I believe the IAC's are sold without a gasket,make sure you have a new gasket before you pull the old IAC. I've also been told it is possible to clean an IAC ,some people have had success cleaning theirs,others haven't but if you want to try pick up a gasket first. One of these warm week-ends I'm going to try cleaning mine in my 96 Cougar 4.6.

 

The IAC valve stands for Idle Air Control Valve. It controls bypass air around the throttle plate at low speeds.

I tried cleaning mine before replacing. The original cleaned valve worked great for a couple months then gave out again. I'd strongly recommend a new one so you only have to R&R once. My original lasted over 50K miles.