Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance Cleaning the IAC

For awhile now I have experienced intermittent serious hanging throttle. I'm talking about when shifting the revs stay where they are or even go higher after hitting the clutch. At first it didn't happen very often but lately occured more frequently as well as surging while at steady throttle. I tested the IAC by applying 12 volts on the pins and heard the click like you are supposed to. I checked it with a multimeter and got a reading within the normal range so I ruled out the IAC. I changed my plugs and wire for the surging but that didn't help. I checked for a vacuum leak but found none. Finally, I thought I might as well pull the IAC and try cleaning it since that didn't cost anything except a little time, a cheap gasket and some carb cleaner. When I first pulled it, it really did not look all that dirty. I expected it to be full of crud. I've driven the car for two days now and no more serious hanging throttle or surging. The car is smooth and throttle response is back!

When I picked up the new gasket before the cleaning (66 cents and not necessary if you are careful) the Ford counterguy told me carb cleaner would melt a plastic part inside and destroy the IAC. He had to agree that cleaning it first made sense because it could work and if not, you would have to replace it anyway, melted or not.

I've already added cleaning the MAF to my regular maintenance routine. I'll now add cleaning the IAC, at the first sign of idle problems.

So you did use carb cleaner? Or did you use some kind of electronics cleaner?

Valvoline carb and throttle body cleaner.

i just started to experience this same problem intermittantly myself recently...it only does it sometimes...now i know what to check out tommorrow....i will be cleaning my iac valve,and hope it works...

I used WD-40 on mine and it did clean the IAC.

Be careful! I started having throttle hang, idle problems, took the IAC off and cleaned it with berrymans. Worked for a while then noticed the hang came back a few days later. Pulled the UIM, cleaned it, the TB, IAC and MAF with berrymans and broke some vac lines. Replaced all of the broken or suspect lines and again reset the ECM. This time the idle was fluctuating at a stand still from 500-3500 and would change to 400-4000 under load.

I chased what I thought was a vacuum leak for weeks, pulling my hair out. Tried using WD-40 on the IAC, cleaned the MAF, no change. Recleaned the IAC and placed a small amount of machine oil on the shaft, no change.

Finally got frustrated and took it to Ford....problem turned out to be the IAC. The part is $73. Try cleaning it but know that more than likely it will need to be replaced.

Oh and BTW the car is now super smooth, no hang and no bucking!!

You must have the gift of seeing the future. Within a week of cleaning my IAC the problems started showing up again. I have since replaced mine and the car runs much smoother with far better throttle control.

By the way, if you know someone that works at a dealership have them get the part for you. The IAC lists for $73. I paid $44 by getting it through an employee.

Some of the best money you've spent huh! I got to the point where I didn't care what it cost to fix. It was driving me crazy because I had cleaned the IAC to the point where it looked like freshly cast aluminum and it was still screwed up. At the time I hyad ruled the IAC out and was pointing a finger at a small vac leak at the UIM causing the DPFE/MAF/TB/IAC/TPS/O2 Sensors.....to analyze and react causing the car to loop.....

I cleaned my IAC several months ago with WD-40 and the car still idles fine. I used a lot of WD-40. I would fill the IAC up with WD-40 a let it soak for a while. I did this several times.

How do you get that bottom 8mm bolt off? I can get the wrench on it but i don't have any room to turn.