***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
08-13-2010, 01:21 PM
#252
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
Just wanted to post my experience in performing the IACV cleaning. First, thanks for posting such a well documented tech page on this subject.
I recently came into owning a very worn '91 Civic DX. Had a blown headgasket and a bunch of other neglected maintenance issues. Obviously, the car was not running. Once the required work was performed, I started the car and it immideately raced to a very high idle, followed by surging and hunting engine speeds. I shut the engine off and began my search for the probable cause and cure. I came upon this article and performed the cleaning of the IAC valve as described. Upon removing the valve, I noticed the coolant tubes to be completely blocked, as well as the vacuum ports of the valve. I poked the crust out of the coolant pipes as well as I could. Further, the carbon was pretty well encrusted on the screen and the belows side was also very dirty. I tried several cleaners including, brake cleaner, which did a less than thorough job. That is, until I tried Dawn Power Disolver, available from grocery store shelves in the household cleaner section. I believe I found it at WalMart. No, I don't work or get a commission for saying this from the manufacturer or vendor. I simply am stating a fact. THis stuff really works! Wear gloves and eye protection as it causes skin irritation. Let the valve steep in this cleaner for a half hour or so and rinse in warm water. I let mine sit for a couple of hours, in a plastic bag, under the sun, prior to rinsing.
Upon reinstalling the valve, the engine starts and runs very well, no hunting or surging and stabilizes quickly to an even idle.
Again, I want to thank the individual who posted this excellent write-up. It saved me hours of frustrating trouble shooting and expense.
Cheers,
Norman C
I recently came into owning a very worn '91 Civic DX. Had a blown headgasket and a bunch of other neglected maintenance issues. Obviously, the car was not running. Once the required work was performed, I started the car and it immideately raced to a very high idle, followed by surging and hunting engine speeds. I shut the engine off and began my search for the probable cause and cure. I came upon this article and performed the cleaning of the IAC valve as described. Upon removing the valve, I noticed the coolant tubes to be completely blocked, as well as the vacuum ports of the valve. I poked the crust out of the coolant pipes as well as I could. Further, the carbon was pretty well encrusted on the screen and the belows side was also very dirty. I tried several cleaners including, brake cleaner, which did a less than thorough job. That is, until I tried Dawn Power Disolver, available from grocery store shelves in the household cleaner section. I believe I found it at WalMart. No, I don't work or get a commission for saying this from the manufacturer or vendor. I simply am stating a fact. THis stuff really works! Wear gloves and eye protection as it causes skin irritation. Let the valve steep in this cleaner for a half hour or so and rinse in warm water. I let mine sit for a couple of hours, in a plastic bag, under the sun, prior to rinsing.
Upon reinstalling the valve, the engine starts and runs very well, no hunting or surging and stabilizes quickly to an even idle.
Again, I want to thank the individual who posted this excellent write-up. It saved me hours of frustrating trouble shooting and expense.
Cheers,
Norman C
08-17-2010, 07:43 PM
#253
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
hi guys, i have a 1994 honda del sol vtec B16a engine. i got a mechanic to clean the throttle body, he did not remove it he just sprays carb cleaner and wipe it. after that exercise, the idle started bouncing. i followed this thread and cleaned the IACV, i also cleaned the FITV, checked the TPS (0.498 volts closed and 4.44 volts WOT), i bled the coolant and took off the negative on the battery to reset ECU. No Dice, i still get the bouncing idle. some more test i did: while the car is warm temperature, i covered the upper hole in the throttle body- it sucked my thumb and the idle went down. I disconnected the harness of the IACV and the idle stopped bouncing and the idle went steady. when i reconnected it, the idle went up to 1600rpm. i turned it off and turned it back on and the idle bouncing started again. the idle bounces between 800rpm and 1400rpm. im suspecting the IACV has gone bad but its just boggles me to see the IACV gone bad right after the throttle body got cleaned, in like 5 minutes. i really dont want to buy that part if i can avoid it, expensive for me. any input/suggestions is appreciated. thanks
08-18-2010, 08:05 AM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
Great post! I had a quick question about maybe taking mine apart. Would this be possible? There is a screw, like a L wrench nut on one of the ends of the IACV. I wanted to take it apart and clean inside. Is this recommended or not needed? Thank you. 
08-19-2010, 07:56 AM
#255
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
I was doing it tonight and it is pain in the axx. Especially removing the bottom hose. The space is very narrow and the location is hard to reach.
finally, I'vedone it and work hard for the people who going to do it!!
finally, I'vedone it and work hard for the people who going to do it!!
09-13-2010, 04:57 PM
#256
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
The function of the IACV a.k.a. Idle Air Control Valve is to adjust the idle based upon the amount of air entering the engine, then the computer reacts to this information by adjusting the cars rpm.
Reasons why you should take it apart and clean it:
-High idle after your car warms up
-Lumpy idle
-Roaming idle
-Hunting idle
-Fluctuating idle
Tools Needed:
Ratchet
12mm Socket
Pliers
Brake Cleaner or Simple Green
Paper Towels
A cooled down engine for at least 2 hours
1) Now you got to locate where the IACV is, pop your hood and it’s located directly behind the intake manifold. It’s actually connected to it. Remove your intake and strut tower bar. (If applicable)
2) Place a couple of rags underneath to catch the coolant spill. Loosen the two hoses running to the IACV with your pliers by squeezing the two clips and moving them away from the end, circled in yellow. DO NOT cut the hoses as they are the exact length and you will have to buy new ones if you do.
3) After doing that remove the harness connected to the IACV on the driver side, circle in blue.
4) Then to finally remove it from the intake manifold, remove the two 12mm bolts, circled in red.
Now that the IACV is removed from the intake manifold make sure that you do not lose the rubber gasket as you need this so that it does not leak after you re-install the IACV.
5) Take your brake cleaner or simple green and start to clean up the inside of the IACV by spray inside the two holes. Continue to do this until no more dirty fluid comes out. Should take anywhere from 5 minutes to 15 minutes. This depending on how old and dirty your IACV is. The gasket can be seen in this picture as well.
6) Once you’re done cleaning out the IACV let it air dry. I let it air out for 20 minutes while I did other maintenance on the car.
Now your ready to re-install it back on the car so follow the steps backwards from 5 – 2
Good Luck
Reasons why you should take it apart and clean it:
-High idle after your car warms up
-Lumpy idle
-Roaming idle
-Hunting idle
-Fluctuating idle
Tools Needed:
Ratchet
12mm Socket
Pliers
Brake Cleaner or Simple Green
Paper Towels
A cooled down engine for at least 2 hours
1) Now you got to locate where the IACV is, pop your hood and it’s located directly behind the intake manifold. It’s actually connected to it. Remove your intake and strut tower bar. (If applicable)
2) Place a couple of rags underneath to catch the coolant spill. Loosen the two hoses running to the IACV with your pliers by squeezing the two clips and moving them away from the end, circled in yellow. DO NOT cut the hoses as they are the exact length and you will have to buy new ones if you do.
3) After doing that remove the harness connected to the IACV on the driver side, circle in blue.
4) Then to finally remove it from the intake manifold, remove the two 12mm bolts, circled in red.
Now that the IACV is removed from the intake manifold make sure that you do not lose the rubber gasket as you need this so that it does not leak after you re-install the IACV.
5) Take your brake cleaner or simple green and start to clean up the inside of the IACV by spray inside the two holes. Continue to do this until no more dirty fluid comes out. Should take anywhere from 5 minutes to 15 minutes. This depending on how old and dirty your IACV is. The gasket can be seen in this picture as well.
6) Once you’re done cleaning out the IACV let it air dry. I let it air out for 20 minutes while I did other maintenance on the car.
Now your ready to re-install it back on the car so follow the steps backwards from 5 – 2
Good Luck
do you know where to buy the rubber gasket for the idle air control valves? i called the auto parts stores asking for them and no carries them i would have to buy a new iacv to get a new gasket...which is just bullsh*t. any help would be great thank you
09-13-2010, 10:50 PM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
yeah im for sure gunna try two o rings together and see where that gets me...i have a b16a with a newer IACV and i was inspecting it today just to do a cleaning of it and the mother had NO flipping gasket on it and im shocked cuz im suspecting this is why my car is running like crap it boggs out in between 1500rpm and 2000rpm sometimes shutting the engine off. if anyone else has any info or mantinence i could or should be doing for this problem of mine it would be a great help!!!
09-14-2010, 12:48 PM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
if anyone has a gasket for an IACV for an obd1 b16a id greatly appreciate it if you can sell me one or hook one up...let me know
09-15-2010, 04:15 AM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
thirsk, You can make your own buy using extra o-ring material. Superglue works phenomenally well to make your own o-ring type seals. You can also use 3Ms super black gasket sealer.
If you need some o-ring stock - Find an old plastic radiator and remove the end tanks by plying the metal flanges off the side of the plastic. There are huge "O-rings" inside the end tanks which you can use to make whatever you need.
Hope this helps. Super glue is great for making o rings - it dissolves the rubber just slightly so its an actual rubber "weld" if you will. Make sure you use the regular glue and not the gel crap. The get is useless junk.
If you need some o-ring stock - Find an old plastic radiator and remove the end tanks by plying the metal flanges off the side of the plastic. There are huge "O-rings" inside the end tanks which you can use to make whatever you need.
Hope this helps. Super glue is great for making o rings - it dissolves the rubber just slightly so its an actual rubber "weld" if you will. Make sure you use the regular glue and not the gel crap. The get is useless junk.
09-15-2010, 04:31 AM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
I recently changed out my IACV with one from a junkyard it worked fine for a while and now it idles high & low when I come to a stop not as bad as my old one though, now I am thinking of cleaning out my old one and putting it back hopeing it works better..
09-19-2010, 04:56 AM
#264
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
thirsk, You can make your own buy using extra o-ring material. Superglue works phenomenally well to make your own o-ring type seals. You can also use 3Ms super black gasket sealer.
If you need some o-ring stock - Find an old plastic radiator and remove the end tanks by plying the metal flanges off the side of the plastic. There are huge "O-rings" inside the end tanks which you can use to make whatever you need.
Hope this helps. Super glue is great for making o rings - it dissolves the rubber just slightly so its an actual rubber "weld" if you will. Make sure you use the regular glue and not the gel crap. The get is useless junk.
If you need some o-ring stock - Find an old plastic radiator and remove the end tanks by plying the metal flanges off the side of the plastic. There are huge "O-rings" inside the end tanks which you can use to make whatever you need.
Hope this helps. Super glue is great for making o rings - it dissolves the rubber just slightly so its an actual rubber "weld" if you will. Make sure you use the regular glue and not the gel crap. The get is useless junk.
They're just o-rings
Think they cost .05$ or a whole pack of various sizes for like 20$
Or you can be real cheap and use rtv
(If you do things the right way its less likely you'll have to mess with it later)
10-03-2010, 08:37 PM
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Re: cheesefries (skinnyshugg [V2])
Nice write up. This should help me out with the problem that i am having right now. I started my car the other day and the RPM was fluctuationg from 500 to 100 and engine almost turning off completely. I would rev it and RPM would still drop. I turned it off and back on and it went away. However, the following day it did it again and wont go away. If its not this it could be my TPS or FITV.
My GSR has this same problem
Did you ever get it fixed?
10-15-2010, 05:19 PM
#267
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
does any1 have any idea what kind of cam i just picked up? it says s2 or 2 on the middle of the shaft its not with me right now and it also says HOT on the intake cam were the dizzy slides in?
10-16-2010, 04:06 AM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
nice write up now can anyone fix my problem.... i built a G23 vtec for my 90 da and its installed in the car and everything works untill you start it. when i start the car with the IACV pluged in to the wiring harness it will rev up to red line all by itself and wont come down but with the IACV unpluged it idles between 1000rpm and 2500rpm
10-26-2010, 05:41 PM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
ok so i did this on my 95 gsr ...and it didnt solve the idling up and down issue it has at all...my car idles from 1000rpm to 3000rpm up and down up and down up and down..its annoying as FU*K!!!....sure would appreciate input on what could be causing it to do so i would really like to get the issue fixxed before winter hits.. ive listened to it idle like that LONG enough to the point im about to go nuts..oh and ive noticed it smells like my car is burning super rich too.yet my car runs fine as can be it dont hesitate or anything .flat out runs great other than the idling issue....but yea any input what so ever is HIGHLY appreciated
10-29-2010, 07:17 AM
#271
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
DELETE YOUR FICV FOR GOD SAKES.
bypass the coolant lines and put rubber caps on the nozzles.
or make a plate with 3 screws and bolt it on and jb weld the hole closed on the bottom.
bypass the coolant lines and put rubber caps on the nozzles.
or make a plate with 3 screws and bolt it on and jb weld the hole closed on the bottom.
11-02-2010, 02:04 PM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
I cleaned mine without taking the coolant hoses off. I just unbolted it from the manifold and sprayed it out with simple green, then just bolted it back up. I would have taken it off but i couldn't get the coolant hoses disconnected.
11-06-2010, 07:13 PM
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Re: ***How-To Clean*** Your IACV a.k.a. Idle Air Control Valve
you don't happen to have a how to swap out a transmission do you?
