IAC valve removal order?
Thread Starter
Registered!!
Joined: Feb 2011
Posts: 19
Likes: 0
Rep Power: 0 
IAC valve removal order?
2000 CIVIC LX 1.6
I have figured out my IAC valve might need some lovin as I am having low idles.
I have found everything on the IAC except how to remove it step by step. They show how to clean it, but its already removed at that point.
I removed my air intake and there is the other half of air filter box attached to the throttle body that I guess has to come off first? I see its attached by a clamp ring that attaches it to the throttle body. I think there is another screw on the left also.
Can anyone give me some advice here? It just seems to be really tight quarters.
Thanks!
I have figured out my IAC valve might need some lovin as I am having low idles.
I have found everything on the IAC except how to remove it step by step. They show how to clean it, but its already removed at that point.
I removed my air intake and there is the other half of air filter box attached to the throttle body that I guess has to come off first? I see its attached by a clamp ring that attaches it to the throttle body. I think there is another screw on the left also.
Can anyone give me some advice here? It just seems to be really tight quarters.
Thanks!
Trance Addict
Joined: Dec 2009
Posts: 1,774
Likes: 0
From: Troy, NY
Rep Power: 217 
Re: IAC valve removal order?
Why can't you use it? Ctrl F IAC Valve, Idle Air Control Valve. It shouldn't be too bad. If it's too much, you should invest in a physical haynes/chilton's manual.
Trance Addict
Joined: Dec 2009
Posts: 1,774
Likes: 0
From: Troy, NY
Rep Power: 217 Re: IAC valve removal order?
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
Thread Starter
Registered!!
Joined: Feb 2011
Posts: 19
Likes: 0
Rep Power: 0 Re: IAC valve removal order?
Thanks for this link MelJ.
I have already read that thread and any other threads here for IAC or Intake Air Control, as well as all Youtube videos with those terms. I found a Civic repair manual online and it was also confusing even more so than the one Newfiedan posted. There are pictures in the thread you linked, but I don't know what step to do first. I can't get at the IAC at all without removing other parts, thats where I need some help.
It just says "remove your intake". But how is that done?
I did get some Carb Cleaner and I already cleaned the throttle body (butterfly valve?) with it and it made a big difference in my pedal smoothness.
I have already read that thread and any other threads here for IAC or Intake Air Control, as well as all Youtube videos with those terms. I found a Civic repair manual online and it was also confusing even more so than the one Newfiedan posted. There are pictures in the thread you linked, but I don't know what step to do first. I can't get at the IAC at all without removing other parts, thats where I need some help.
It just says "remove your intake". But how is that done?
I did get some Carb Cleaner and I already cleaned the throttle body (butterfly valve?) with it and it made a big difference in my pedal smoothness.
Last edited by scolecite; Feb 20, 2011 at 08:22 PM.
Trance Addict
Joined: Dec 2009
Posts: 1,774
Likes: 0
From: Troy, NY
Rep Power: 217 Re: IAC valve removal order?
Hopefully Newfiedfan can add to this. It really isn't too complicated. My car came with a short ram intake, so a few of my steps may be different if you have the stock filter and box.
1. Disconnect battery ground(negative)
2. There is a sensor that goes into the box. Not sure off the top of my head which one, maybe the MAF? Anyway, unplug that.
3. The hose going into the throttle body has huge hose clamps which can't be missed. Take a flat head and unscrew them and remove the hose from the TB.
There may be a few bolts underneath the air filter box which may need to be unbolted. The process is pretty easy and straightforward. You should really give that manual a look over because it should list all the steps to remove the intake from the IM.
That's a photo of my bay. I can't really get a decent zoom for it, but you should be able to see where it hooks up and what needs to be removed for the most part.
1. Disconnect battery ground(negative)
2. There is a sensor that goes into the box. Not sure off the top of my head which one, maybe the MAF? Anyway, unplug that.
3. The hose going into the throttle body has huge hose clamps which can't be missed. Take a flat head and unscrew them and remove the hose from the TB.
There may be a few bolts underneath the air filter box which may need to be unbolted. The process is pretty easy and straightforward. You should really give that manual a look over because it should list all the steps to remove the intake from the IM.
That's a photo of my bay. I can't really get a decent zoom for it, but you should be able to see where it hooks up and what needs to be removed for the most part.
Last edited by MelJ; Feb 20, 2011 at 08:32 PM.
Registered!!
Joined: Jan 2011
Posts: 356
Likes: 1
From: Saskatoon
Rep Power: 190 Re: IAC valve removal order?
You are going to have to unscrew the clamps holding the air intake tube to the throttle body there will be some 10mm nuts holding it onto the body that will have to be removed as well, if you cleaned your throttlebody then you already know those steps. What engine do you have? It is stamped on the engine where the trans meets the engine either a d16y8 or d16y7. If its the d16y7 then its very easy to get to, the d16y8 is a little more complicated but the pics posted give you a good idea. Get a haynes manual it will give you a better breakdown on some of the general maintenance. Steps in the pics start at the very first one in the pic and then to the last.
Thread Starter
Registered!!
Joined: Feb 2011
Posts: 19
Likes: 0
Rep Power: 0 Re: IAC valve removal order?
Thanks for your latest post MelJ. I just went and took some photos of where the IAC valve is on my car. Its packed under and behind a lot of stuff. It seems like everyone else's is more accessible?
Also Newfiedan, I only wiped the butter fly part with carb cleaner to get the deposit off the valve, I only had to remove the air filter
Also Newfiedan, I only wiped the butter fly part with carb cleaner to get the deposit off the valve, I only had to remove the air filter
Last edited by scolecite; Feb 20, 2011 at 09:10 PM.
Registered!!
Joined: Jan 2011
Posts: 356
Likes: 1
From: Saskatoon
Rep Power: 190 Re: IAC valve removal order?
undo the clips for the air filter then remove that box off the throttlebody, there should be 2 (if memory serves) nuts that help hold the box on, as well as a clamp that holds it onto the throttlebody. Once thats out of the way it will much easier to access. the idle air control is attached to the throttlebody.
Thread Starter
Registered!!
Joined: Feb 2011
Posts: 19
Likes: 0
Rep Power: 0 
. 
Thread Starter
Registered!!
Joined: Feb 2011
Posts: 19
Likes: 0
Rep Power: 0 Re: IAC valve removal order?
Ok I cleaned the goddammed thing! 
What a pain in the ***. I had to remove the bracket that holds the throttle cable, in addition to the air box. And getting to that clamp on the air filter box was difficult, thank god I had a really small socket wrench.
TWO THINGS:
1. I cleaned the IAC well and exposed throttle body area, then I cleaned grommet and coated in oil. I screwed back the IAC but the screws never really got tight, they just stayed at a medium tightness but never felt like they stripped. All four felt like that, I thought it was strange. I was expecting the screw to stop at some point but they never did even though IAC was tight against throttle body. Any ideas?
2. How long does the ECC take to reset. After I cleaned IAC, I let the car idle for 5-10 min then drove it for 30 min. In the beginning I seemed to have the same idle problem, but towards the end of the ride I think it went away.
I guess its trial by
here. But I passed. 
What a pain in the ***. I had to remove the bracket that holds the throttle cable, in addition to the air box. And getting to that clamp on the air filter box was difficult, thank god I had a really small socket wrench.
TWO THINGS:
1. I cleaned the IAC well and exposed throttle body area, then I cleaned grommet and coated in oil. I screwed back the IAC but the screws never really got tight, they just stayed at a medium tightness but never felt like they stripped. All four felt like that, I thought it was strange. I was expecting the screw to stop at some point but they never did even though IAC was tight against throttle body. Any ideas?
2. How long does the ECC take to reset. After I cleaned IAC, I let the car idle for 5-10 min then drove it for 30 min. In the beginning I seemed to have the same idle problem, but towards the end of the ride I think it went away.
I guess its trial by
here. But I passed. Registered!!
Joined: Jan 2011
Posts: 356
Likes: 1
From: Saskatoon
Rep Power: 190 Re: IAC valve removal order?
yeah you should be good then, if it crops up again just reset the ecm and then allow it to idle till warmed up then shut the car off and let it sit for abit then restart and good to go, honda ecms are pretty decent at relearning idle fairly quick though for those who screw the order up.
Registered!!
Joined: Oct 2012
Posts: 6
Likes: 0
Rep Power: 0 Re: IAC valve removal order?
I am facing the exact same issue and need to remove the air filter box first. Could not find a detailed info how the air filter is installed. Does anyone know where/which is the "clamp" that scolecite was referring to? thanks.
Registered!!
Joined: Oct 2012
Posts: 6
Likes: 0
Rep Power: 0 Re: IAC valve removal order?
my car is 1999 civic DX, no-vtec y7 engine. the IAC valve is under the air filter cleaner box.
To clean the IACV, I need to remove the air filter box first. Trying to find out how many bolts/nuts/clamps and where they are. Anyone can help? thanks.
To clean the IACV, I need to remove the air filter box first. Trying to find out how many bolts/nuts/clamps and where they are. Anyone can help? thanks.
Registered!!
Joined: Jan 2013
Posts: 1
Likes: 0
Rep Power: 0 Re: IAC valve removal order?
yeah you should be good then, if it crops up again just reset the ecm and then allow it to idle till warmed up then shut the car off and let it sit for abit then restart and good to go, honda ecms are pretty decent at relearning idle fairly quick though for those who screw the order up.
i'm having idle problems too' i removed the IACV and cleaned with carb cleaner' came up really good' put it back on then removed one batterey lead to reset ECU' problem is still there but gone worse???? engine really lumpy? also when engine is warmed up' when i rev the engine the needle drops to nearly cutting the engine out? any ideas...
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
mievil
Mechanical Problems/Vehicle Issues and Fix-it Forum
2
Apr 28, 2015 11:02 PM
