How to clean the IAC?

I've seen several instances where one of the suggestions to resolve a problem was to clean the IAC (idle air control valve). Could someone give me detailed description of how to do this?

It would also be helpful to know if there is a way to test the IAC to verify that it is operating properly.

Thanks, in advance!

I've seen several instances where one of the suggestions to resolve a problem was to clean the IAC (idle air control valve). Could someone give me detailed description of how to do this?

It would also be helpful to know if there is a way to test the IAC to verify that it is operating properly.

Thanks, in advance!

Remove it and spray the plunger and passages with carb or TBI cleaner and also clean tbi with a tooth brush and carb or TBI cleaner.
If it is working right it will hold your idle speed right.
With no check engine light.
Put it in gear or turn on ac and see if idle stays the same and does not idle to fast or dye..
If so it is working good.
MT

Please forgive my ignorance... I'm still learning... what is "TBI"?

Not sure what is intended by TBI, but in the text of the message, I would say that "Carb or Fuel Injection cleaner"...perhaps Throttle Body Cleaner? if there is such a named cleaner.

I have even used WD-40 to clean mine..........also "Seafoam Deep Creep"....Deep Creep being the spray version of seafoam.....same stuff, just in a spray can.

Way to do it would be to remove the IAC from the top of the throttle body and spray a liberal amound of the stuff inside while holding the IAC in such a way that the stuff runs out as you spray.......
This way you will be rinsing any dirt that you work loose right out.
Drain into a towel......or container.....not into the engine compartment.
The WD-40 and Seafoam has some oil that will lubricate the workings.
If not successful with the cleaning, you will need to buy a new one.
It is an easy repair (Cleaning or replacement) that you can do yourself.
2 small bolts and 1 electrical connection....and it is right where you can easily get at it.

I cleaned my IAC several years ago when I did the lower intake gasket repair. The advice given by MT-2500 and Wiswind is excellent and basically what I followed.

In my experience, I also had to get the IAC into bright light and use a small screwdriver to gently brush some of the crud off of the little disk inside; for whatever reason, the cleaner did not get this small buildup off. It caused my idle to be too high and I got a CEL for, you guessed it, "idle speed too high". If the IAC is working properly, your idle will be at the proper rpm's which is around 750, I believe (someone please correct me if I am wrong on this number).

This may help

http://leckemby.net/windstar/windstar02.html

I did not write it though

Thanks for all of the responses. I appreciate it very much!

The issue that I'm having is this:

I originally got a "Service Engine Soon" light, used a code scanner and found a P0401 trouble code. I used Wiswind's pictures and advice (along with others') regarding cleaning the EGR ports. When I removed the intake plenum, I found that the ports were clogged. Ports 2, 3, 5 & 6 were almost completely clogged. The contamination in all but port 1 was "gooey sludge". In port 1 was more like black soot. I couldn't use a shop vac to get much of the crud out, so I ended up washing the vast majority of it into the cylinders with carburetor cleaner. Boy did it smoke when I finally got it to start!

It ran OK for a little bit (an hour or so), but then began to have trouble idling. It was especially noticeable when I took my foot off the accelerator quickly and braked hard. The idle speed would drop below 500 RPM and the engine would die. The "Service Engine Soon" would eventually illuminate and I would find a P0171 code “showing” with a P0174 code “pending”. I checked for vacuum leaks, but didn’t find any. At this point I suspected that the way I had washed the crud into the cylinders had clogged some of the fuel injectors.

I’ve run about 1 ½ tanks of fuel (mixed with Berryman’s “Chemtool” through the system without much improvement. I checked for vacuum leaks again and found the gasket around the MAF sensor wires loose (where the wires entered the bottom of the air cleaner compartment). After I reseated the gasket, the situation improved, but I still have sporadic problems with the idle speed dropping below 500 RPM. The engine hesitates, the oil pressure and brake lights flicker and it’s stalled once, but usually it “revs” back up past 500 RPM. I’ve used a code scanner and don’t see any codes either “showing” or “pending”. I’m wondering if the IAC is not doing it’s job and keeping the idle speed high enough.

By the way, this is a '98 Windstar with a 3.8L engine.

Please let me have benefits of your expertise regarding my situation. Thank you in advance!

Please forgive my ignorance... I'm still learning... what is "TBI"?
Sorry about that. I should have said TB/throttle body.
The thing with the butterfly in it where air goes i the engine.
And they do make a special TB cleaner.
CRC makes it in a spray can.
If the IAC is not controlling the idle it has a problem someplace.

Should I have used a different method to clean the EGR ports?

The "Service Engine Soon" would eventually illuminate and I would find a P0171 code “showing” with a P0174 code “pending”. I checked for vacuum leaks, but didn’t find any. At this point I suspected that the way I had washed the crud into the cylinders had clogged some of the fuel injectors.

I’ve run about 1 ½ tanks of fuel (mixed with Berryman’s “Chemtool” through the system without much improvement. I checked for vacuum leaks again and found the gasket around the MAF sensor wires loose (where the wires entered the bottom of the air cleaner compartment). After I reseated the gasket, the situation improved, but I still have sporadic problems with the idle speed dropping below 500 RPM.

<snip>

By the way, this is a '98 Windstar with a 3.8L engine.

I'm sorry I don't have anything to add to help you but you may have helped me. Are you saying your 171 and 174 codes and SES light went away after reseating that wire plug for the MAF wires?

I've been trying to find a vacuum leak and I've noticed looseness in the same part and after reading your post that sucker (pun) is now my prime suspect.

Anyone have any ideas on how to get that thing in there firmly? Maybe some well placed electrical tape? What about where the PCV vent tube enters right next to it? I'm not happy with the way that thing just kind of hangs there either.

BTW, I've cleaned my IAC in the way previously described here, it's fairly new but I cleaned the intake and EGR ports so why not the IAC too. It seems to idle OK and I suspect it will idle better once I find the source of these codes.

Freakzilla69 (http://www.automotiveforums.com/vbulletin/member.php?u=483438), you are correct in your understanding. Once I reseated the gasket on the bottom of the air cleaner compartment (where the MAF sensor wires enter), the SES light and the P0171 and P0174 codes stopped appearing (at least for the time being). :grinyes:

If I remember correctly, the gasket on my vehicle has ribs around the part that actually goes into the opening. This appears to seal the opening and helps keep the gasket in place.

Freakzilla69 (http://www.automotiveforums.com/vbulletin/member.php?u=483438), you are correct in your understanding. Once I reseated the gasket on the bottom of the air cleaner compartment (where the MAF sensor wires enter), the SES light and the P0171 and P0174 codes stopped appearing (at least for the time being). :grinyes:

If I remember correctly, the gasket on my vehicle has ribs around the part that actually goes into the opening. This appears to seal the opening and helps keep the gasket in place.

That's awesome news to me! Mine is just as you described and it's very loose, I hope that's my problem. Maybe a little sensor safe sealant will help hold it in there?