Very High Idle 2-3k

TBIRD35

Registered User
The car had been running fine just went to gas up left the station an all of a sudden the engine began to race by itself. I pulled over put the car in park the idle went to 3k? I checked the throttle body to make sure the butterfly wasnt sticking the linkage was ok, and I didnt see any other kind of problem. I took the car back home asap driving in od to keep the revs down. I checked the throttle positon, an map sensors; both fine. When I shut the engine off there was a howling noise, kinda figured was the super charger? I'm not sure where to look for the EEC codes and or what I should be looking for in this case. Please I need HELP!
 
Last edited:
your high idle is because

you need to get a new IAC idle air controler that is the little black thing on the side of the throttle bodythe bigger black thing with the plug in on it thats why you are idling do high you replace that and you are good to go. good luck Jason
 
Definitely the IAC. Only use the Ford replacement as the units you can buy at AutoZone or Advanced will NOT work. The Ford unit is around $100!
 
TPS

It might be the tps also, I had the same problem. I called a guy at five star ford and he said to try this first.

one aad chef
 
Same Experience

Hey, it took me forever trying to figure this out as well. I went to Autozone and got an IAC valve and it went on backwards. It doesn't work. I finally got an IAC valve from the ford company and my idle returned. My car was doing the exact same thing. Make sure you get it from the ford company. All others will not work, there are no shortcuts. You can try cleaning it first, sometimes that works. I went ahead and replaced my TPS also since I had the IAC valve off anyway. Long story short, it runs good now.
 
there is only a throttle position sensor and a air bypass valve on the throttle body no IAC.I put a Air Bypass Valve on mine from NAPA and it still does what you's are having problems with.I will try FORD'S .Texas Star Ford is the cheapest dealer that i have found.
 
The Idle Air Control Solenoid is commonly abbreviated as just IAC.
It is also referred to as a Idle Bypass solenoid, Idle air control valve,.. pick any 3 of the following words and make up a part name:

Air
Idle
Bypass
Control
Solenoid
Valve

e.g.
Air Idle Bypass
Idle Air Bypass
Air Bypass Control
Air Bypass Solenoid
Air Bypass Valve
Air Idle Control
Idle Bypass Control,
Idle Control Solenoid
Idle Bypass Valve
Idle Solenoid Valve
Idle Bypass Solenoid
Idle Control Valve
Bypass Control Solenoid
Bypass Control Valve
Bypass Solenoid Valve

I think you get the point. The main point however is to know that most aftermarket parts are valve open, and will not work, and cannot be made to work, on the SC due to the placement of the oil filler tube. You must use either the Motorcraft OEM part, or an equivalent valve closed part. The inside will have a nylon diaphragm and the valve will be closed.
 
Then i guess it's fair to say that Napa ripped me off,because it is not working.So now you all know Napa's Air Bypass valves don't work either.
 
Actually, some of us already knew that.

You should be able to take it back.. just tell them that it wouldn't fit, then explain how the Oil tube blocks it from going on backwards.. Don't tell them you installed it, tried it out and it didn't work.

"Well Mr. Smith, did you install the part?".. "No, it wouldn't fit".
This will be followed by them looking through about 5 manuals and typing on their terminals for another 5 minutes and scratching their heads and saying "well.. it shows this as the part" to which you will reply "well, it may be for the generic Ford, but it doesn't fit the supercoupe.".. Then you go on the offense for a few minutes and say "Why are you listing a part which is not a 1 to 1 OEM replacement. What were the boneheads at Borg Warner thinking when they came up with this piece of crap?"

The tell tale sign without looking any further is if it comes with the plastic wire bundle strapped onto the IAC body, its the wrong part. Now that you know what to look for, you might be able to find one at Carquest or Advance, or if you don't want to mess with the search, go to Ford. For a Ford part, they're not all that expensive.
 
I installed this about 6 months ago and it fit on the right way and it also had the wiring atached to it like you said but i threw away the box and im not sure where the wiring is because i just used the factory harness so i guess i gotta eat this part unless i get ahold of borg warner and complain about it,also NAPA has a no return policy on electrical parts.
 
You're saying you've suffered with a fast idle for 6 months?

I went though this 2 yrs back. Got a part from Pep boys.. installed it... didn't work.. took it back immediately and got a refund. Then went down the road to Orielly's.. same part, different label, then to Autozone.. same thing again!.. finally went to Napa.. same freaking part yet again.. First time Napa's let me down.

Ended up going to Ford, crack of dawn on a Monday morning of course, and got the part right away. But have heard that either Advance or Carquest has the proper part. Yes, it bites. I'd at least let the manager at Napa know about it, probably wouldn't do you any good, but at least they could try to correct the mis listing.
 
I bought the car with the knowledge that it wasnt running right.So i started looking for the problems .I replaced the IAC first because the corner of the original was broke off by a previous owner.I replaced the part with a NAPA part but wasn't sure that was the reason with the high idle because of all the other problems with this car running like **** until i started looking into this forum.I didn't know there was such a forum about these cars.I sort of stumbeled onto it.I just talked to NAPA today and he said that with out the box he wasn't sure if they (ECHLIN) would take it back but he will try.He will tell them that it is defective and give me a credit only if they give him a credit for it.Thanks for all you help!!!Maybe this will get me alittle closer to getting this awesome car straightened out.I also have a lean problem with it,i put two new o2 sensors on it and was getting no codes of a lean or rich mixture until i cut open the cats and knocked the guts out and welded them shut.Now i am getting a lean code off both banks........why?
 
Does anyone have the correct FORD part # for the IAC (or any of it's aliases)? I need to get one. I have the classic symptoms of high (racing) idle and the "Dying Goose" sound so I'm near possitive this is my problem.
Thanks,
Brandon
 
I bought one from Auto Zone years ago and it didn't even fit.

When I put my SC back together after the head gasket job I had a 3k idle and in minutes red hot headers and coolant temp pegged.

What happens is the IAC is set to bypass a certain amount of air around the blade of the throttle to keep the car idling at the specified RPM. Well the diaphragm in mine was torn somehow and it was letting a lot of air in. The car looks at the TPS sensor to determine how far the throttle is opening and then compensates the correct amount of fuel. With all that extra air coming in and only the amount of fuel required to keep it at say 900 rpm. There was an extremely lean condition which is what caused it to turn my headers bright orange.

I got the ford part the next day from a dealer about 30 minutes from here (only one who had one in stock). I paid around $95 for it. Came home put it on, and the car ran fine. I did unhook the battery and let it relearn idle. It's been fine since then.

I would advise against driving the car until it's fixed because it could cause you to run very lean and damage your engine. I remember it would also make a goose honk sound when I turned the car off.

Good luck.
 
Back
Top