HELP - URGENT! Out of control idling

[SyberTiger]

Hey fellas...I'm 500 miles from home visiting my parents. My Explorer is sitting in a shopping center parking lot several miles from their house. I drove the vehicle several times today without problem but a couple of hours ago she started acting up. Let me describe the problem:

When I start the Explorer up I have out of control idling. That is, it starts up without problem but idles at 2200 - 2400 RPM. The accelerator peddle is not stuck and I tapped it several times to see if that makes a difference but alas it does not. There are NO engine codes and NO service engine soon light.

Anyone have any clues as to what is causing this? I've never seen this problem before. Please click on my vehicle profile to see the details of my vehicle configuration. Thanks!

 

[matt0248]

bad IAC. mine did the same thing about two years ago. IT would get worse the warmer the engine got. It would start in the morning and seem fine. but, 2-3 miles later sitting at red lights it would be idling in gear at 1200 RPM's. NOthing I tried would fix it except an IAC. I tried cleaning it but that did not work as it was not stuck or sticking. I ended up replacing it. Get and Motorcraft one if you can. the "store" brand ones do not work so well.

 

[vipersinu2]

try unplunging the idle air control (iac) see what happens. sometimes you can clean and grease (IAC) and that will fix problem. also there can be a vaccume leak on the intake gasket, spray staring fluid around intake see if idle increases. also the mass air flow sensor can be goin bad. try unpluging and see what happens.

 

[SyberTiger]

I went back out to the shopping center 10PM last night with some tools. Unplugging the MAF did not have any effect on the fast idle. Unplugging the IAC caused the fast idle to go away but then as you would expect the engine doesn't idle...it just dies. What I did was keep the IAC unplugged then drove it the 2 miles to my parents house using two feet to drive. One foot on the brake and one foot on the accelerator to keep the engine from dieing when I hit a stop sign.

I'm also thinking that the problem is the IAC.

 

[SyberTiger]

Yup, it ended up that it was the IAC that died on me. I suspected my IAC was going bad several weeks ago when I noticed that at stop lights the engine had a slight "jumpy" RPM issue. That is, the RPM would jitter back and forth from around 700 to 800 RPM but it was a constant jitter.

Anyhow, I was surprised how the idle shot up to 2200+ RPM when the IAC finally died. I ended up getting a BWD (Borg-Warner) IAC from AdvancedAuto for $61. My Explorer uses Motocraft part 2R3Z9F715-AA (sometimes listed as CX-1785). It would appear that the BWD IAC is identical to the OEM IAC as much as to suggest that BWD is probably the supplier to Motocraft.

Well, a new IAC fixed my reported problem and I'm here to thank those who gave their input on this topic.