What is the part just under the throttle body opening? It looks like it recirulates through a rubber pipe back into the stock plastic air tube. Will this also need to be tied into my IC pipes? Any mods needed? What's it do?

I've got a 94 1.8 in case it doesn't exist on some other years. I see it on Braineacks pics of his engine tear down. Just trying to figure out these last bits I need to create parts for before building. Hadn't seen this part discussed before. Didn't know there were other tubes (more T's needed) that I'd have to tie into the IC pipes other than the recirculated BOV.

 

It is the AIC i believe. If it is the AIC it is nothing more than an autmatic choke valve that feeds us aux air to idle, on cold start ac running etc. You can run with it blocked as i have for quite some time you just have to tune around it or plumb it in. To plumb it in o mine i just put a nipple close to the TB and ran into it.

 

AIC valve. If youre running the AFM you need to pipe it in with your intake system, but if you are running a MAP sensor, you can just put a little filter over it ... or have it the other way, or block it off but then you loose idle control.

 

Sticking with bandaids for now, I guess I'll have to plumb it in. Thanks guys.

 

This answers my question, I was wondering if I could put a little filter on it when I delete the AFM this weekend. That would make the intake pipe work so much easier.

Does any one have a picture of a filter on it or a part number for the filter that they used?

 

i believe the only options you have is to plumb it into the charge/intake pipes or plug it up because the aic is controlled with vacuum thus a filter can cause a big vacuum leak...can someone else chime in?

 

It "IAC" (idle air control) valve is electronically PWM (pulse width modulated) controlled by the ECU. If you don't pipe it back into the intake you'll leak boost thru the valve. The engine "leaks" vacuum thru the IAC and that's the whole purpose of it. This small amount of air bypassing the throttle butterfly is how the ECU controls the idle rpm. I don't recomend sticking a filter on it. I don't recomend plugging it up. Correctly pipe it into the IC outlet to throttle body pipe.

You can use the original hose. Just swing it around and it lines up with most setups where the charge pipe comes up to the throttle body.

 

I have mine open. As others have mentioned you can just place a filter over it. If you're going w/ a standaloen (w/ MAP sensor) then you can just leave have the filter over it. HOwever, if you're using the AFM then you'll want it plumbed up to the intake.

 

You loose boost if your boosted. I know I dropped a pound of boost when I left it off.

 

well when i was installing my custom intercooler pipes...i left the iac nipple open and the car would start up and die because of the huge vacuum leak...the only solution i had was to plug it up/reroute it back to the mani or plumb it back into the charge pipe....but the problem with rerouting is the nipple on the iac was huge, the size of a nickel....so i had a hard time finding a vacuum hose to plug up so i drilled and tapped my charge pipe to accept the hose...Im i talking about the wrong sensor?

 

I have run for over a year with mine plugged idle can be tuned but it is abit harder, you definetly need to plum it into the tract if you want to run AC etc at idle. OE i did the same thinh the hose is 3/4 or so i believe a simple bung close to the TB, will work just fine.

 

You were still using the maf weren't you? It's not so much a vacuum leak it's an airflow leak not being detected by the maf. Sounds like your talking about the right line. You have it routed back to the charge pipe right where it needs to be.

 

thanks guys...when i was building my diy kit i forgot all about it...but i had to tap my charge pipe for it.......thanks guys