What does that stand for? im having idling problems and someone told me to look there and clean it. does anyone have a diagram of where it is and how i can clean it? Please i would really appreciate it. Thanks!

 

It stands for Intake Air Control Valve or electronic air control, its #16 in the diagram. There is a filter (#18) that tends to get dirty over time and cause bad idle. Thats where you need to check.

 

wow that looks pretty complex to me...
hmm... where is that peice located exactly?

 

its right on the front of the intake and it comes off with 2 12mm bolts on the front of it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by delguiner &raquo;</TD></TR><TR><TD CLASS="quote"> where is that peice located exactly?</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Revi-Ra &raquo;</TD></TR><TR><TD CLASS="quote">
<U>its #16 in the diagram</U>. There is a filter (#18) that tends to get dirty over time and cause bad idle. Thats where you need to check.</TD></TR></TABLE>


Remove the 12mm bolts on the front (#27 and 28), then remove the coolant line on the bottom and the electrical connector. Then once you have it off, look on the side that is flush with the intake manifold. There is a screen that can become clogged with carbon and cause an idle problem. Clean the carbon out and reinstall.

 

if you think it might be going bad check the wiring. i thought mine was bad and was about to spend $260 on a new one. Turned out to only be the wiring from the iac to the harness

 

ok i went to see my mechanic and he said the 2 points on my timing belt were off... could that be it too? or timing belt has nothing to do with idling?

 

So you've removed or changed the timing belt recently? It's easy to get cam timing off by a little bit when reinstalling.

If the timing is off, your car will definitely be idling crappy. Definitely get that fixed first.

 

OK so basically before even touching the IACV i should wait for the timing belt to be fixed and stuff..( iheard a lot of ppl have problems after they clean the IACV). I mean my idle is very jumpy, sometimes high and sometimes low. its always different. There is no constant. like when the engine is cold the idle will jump 200rpm at a time... e.g. 1000-1200 back to 1000 and then back up to 1200, but eventually that will stop. and then thats when the idle is very unpredicatbale

 

you may just have air in your cooling system...
try bleeding air via the top of the thermostat housing.
when i first swapped, my h22 idled like that and after bleeding it fixed the problem perfectly.

the engine uses a small coolant hose to provide accurate coolant sensing under the throttle body, connects to the thermo housing.
it should be easy to imagine how some air near the bleed bolt could affect the hose and related sensor.

~boom

 

dude where can i find that please? id like to try

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by delguiner &raquo;</TD></TR><TR><TD CLASS="quote">dude where can i find that please? id like to try</TD></TR></TABLE>

clean your IACV first, that will probably fix the problem

 

there something that seems to be getting in the way of the second bolt... im guessing i have to use a wrench for that one...

 

blead the coolant system....i had a 88 prelude si at werk with the same problem...damn o ring to the distributer was bad and it was leaking oil on a coolant bypass hose and eventually started leaking coolant...replaced the hose and o ring....and blead the system and now it runns beautifull...


iac motor allows air more air in bypassing the throttle plate when car is under load to conpensate and bring the rpm's to same speed b4 the load...if the iac was bad...yo'd have and extremely high idle...as is there was a vacuum leak..

oh yeah the bleeder should be located near the thermostat housing

 

I have a similar problem, my idle surges when it's idleing but the thing is, when I unplug the connection from the IACV, it idles normal but it throws a check engine light. Once I plug it back, the CEL is gone but the idle keeps surging. Is this a sign that it is my IACV?

 

does anyone have a diagram of the thermostat housing, and can kinda show me how to bleed it please?

 

doubt it's your coolant,

check what otehr said above and all vacum lines. One slightly loose will cause idle surges

 

same as my problem ,does any one know the answer to that?is it the iacv
cause cleaning the screen and bleeding doesent help this would answer a lot of peoples questions.

 

so i should not remove the the IACV and clean it cause it doesnt help right?

 

if you dident do it yet just do it it takes only 5 mins,

 

i dont know dude
its funny my idle started messing up pretty recently
and i thought it was a leak in my MAP sensor vacuum hose (which i discovered when i was looking for the problem). however repairing the MAP vacuum line did not help. except my engine runs like **** till its warmed up and then its great across the powerband. i had 2 cracked fuel injectors last week, had to get my spares rebuilt by RC, and the car was running like total ****. changed my NGK blue wires out for brand new OEM honda wires and the car ran 30% better. got my cleaned injectors from RC and threw them in, car runs like a dream now...except for when the engine is cold. however adding more fuel when the engine is cold seems to help the problem, it has to be air/fuel related but there is no code yet. already ordered a walbro 255lph 4g prelude pump. so now the only thing it can be is the FPR. im going to find the problem tomorrow.

~boom

 

dude please please please let me know, sounds like we have the same problem... thanks man!

 

Allright, so what i did was take off my IACV and cleaned the little filter. I couldnt actually get the filter off, so i used an old toothbrush to clean it, its still the same really. not much change . Im going to see the mechanic on tuesday cause the timing belt points were a little off. could that be it?

 

anyone?

 

Without any more input on your end, there's nothing else to suggest. Like I said already, if the cam timing is off, that's your problem. But is there any reason why the cam timing would be off? Like, has the belt been removed lately? Or do you hear a rattling that would indicate your tensioner is bad & the belt might have skipped a tooth or two?