Location and Cleaning of AIV

Post by **Snakeman240** » Thu Nov 07, 2002 8:27 pm

I am pretty sure that the AIV in my 1992 240sx is on the driver's side of my engine bay (someone please tell me if I'm wrong). I have been having some performance problems (i.e. sometimes unstable idle, running rich, occassional bog down) and I have heard that a dirty or clogged AIV can cause this. I was wondering how I should attempt to clean the AIV and what should I use. Should I take the whole thing off? Any help would greatly be appreciated. Thanks alot. -Snakeman240

Post by **R240NA** » Thu Nov 07, 2002 8:27 pm

Remove it. Cap the intake pipe port and the exhaust manifold port. You won't see any degradation of emissions and it will clean up the motor a little since it's no longer breathing exhaust gas. Nissan actually sells a pipe plug now that's called 'AIV plug', designed for the very purpose.

Post by **Dattebayo** » Thu Nov 07, 2002 8:27 pm

cap the aiv, huh? ok so which hose is it on the drivers side? so why did they put it there if it is just some crap?

Post by **rbduck** » Thu Nov 07, 2002 8:27 pm

Do any of you have the Nissan part number for this AIV plug?I called the local nissan dealer here in Little Rock. He said he's been the Nissan parts business and there is not and never will be a nissan part like that. He refused to even try to look it up. So, if any of you have the part number I want to call this guy back with the number. THanks

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

hes obviously in the wrong business then because the AIV is the black little box near the intake box that circulates exhaust into the intake. But there is no plug for it from Nissan that i know off.

Post by **rbduck** » Thu Nov 07, 2002 8:27 pm

Thanks Nismo. It was R240Na that said Nissan had the part. If Nissan doesn't have it I would like to know the size. I'll take a look this weekend and see about removing the AIV.I just had a rebuild K24E SOHC installed an it idles rough. It runs extremely well otherwise. I'm either going to remove the AIV or at a minimum, take it apart and clean it.. I'm going to check a few other things also. I looked at the wires tonight and detect no sparking from the wires. I'll figure it out . THe only problem I have right now is time to do it. Thanks Again

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

Whoa i missed R240's post. I'll check at my Nissan dealership tomorrow for that part. I also have a 90 240SX and i removed the whole AIV system. I just left the metal pipe that comes off the header and capped the end off. I really want to get rid of this metal pipe also. If the dealership sells the cap to cap it off at the header, im going to the dealership first thing in the morning

Otherwise its off the homedepot or ace hardware.

Post by **rbduck** » Thu Nov 07, 2002 8:27 pm

LOL..Nismo...I think we still havea misunderstanding here. I'm interested in the cap that you put on the pipe from the header to close it off. What size and what kind of threads does it have? I've read where guys have bent and crimped it. I don't really want to do that....Thanks Again..

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

thats what im talking about, the metal pipe/tubing that comes off the exhaust header and goes to a black box near the intake box. there is also another egr piping coming off the exhaust manfiold and goes directly to the intake manifold. I just need the fitting to cap off the hole the metal pipe would leave behind.

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

Hmm, ill try finding out if the dealers do carry them, if not ill post the thread count and size i get off the tubing for a cap.

Post by **rbduck** » Thu Nov 07, 2002 8:27 pm

Ohhhhhhh I see. I just had an engine rebuild. I've had the car back a couple of weeks now and I've looked at the AIV. My problem is that I really haven't looked close enough to know what I'm talking about..LOL...I plan on removing the AIV this weekend if I have the right stuff to cap off anything that needs to be.

Since the rebuild, the engine has run very well, but when ideling, it runs rough. Also if you give it a little gas, it seems to return back to the normal idle rpm very slow from about 1500 rpm and down. It may not be the AIV, but it's a good place to start. I went out last night and looked at the engine running in the dark to see if there is any sparking, I didn't see any. I do plan on replacing the plug wires anyway.

Post by **nismo240** » Thu Nov 07, 2002 8:27 pm

so if i take out the whole aiv unit ...this should help my car with no problems? weill i know i have to cap off some piping...but i will find out and check back with ya'll to find out the threading! thanks....

Post by **91nis240** » Thu Nov 07, 2002 8:27 pm

oph my gosh guys im in this exact delema if you have read my post on the technical forum about my hs header! i need to plug my aiv hole, ive checked home depot and cant find anything t o plug that whole!!! im guess im gonna give the dealer ship a call

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

I went to the dealership and the guy said Nissan does not make that part (AIV cap) since it would mess with the emissions and thats a big no no.

I didnt get a chance to go to the hardware store today but I will tomorrow (thursday) since im off. A nice short bolt would be perfect to block it off.

Post by **nismo240** » Thu Nov 07, 2002 8:27 pm

all you have to do is take the pipe coming from your exhaust and take it to a place where they weld and have someone weld up the hole....it is that easy...you can pay $5 in stead of $20 buck for a plug at the dealership! your welcome

Post by **SeVa-S13** » Thu Nov 07, 2002 8:27 pm

Newbie question here - is all I have to do is block off the line going from my intake box to the AIV somehow? (I can do it easily enough) And what does this accomplish? Isn't the point of that whole thing to let exhaust flow better?

Post by **rbduck** » Thu Nov 07, 2002 8:27 pm

As far as I know. the when you start the engine cold the exaust header creates negative presure and pulls air directly from the filter box. This extra oxygen causes the cat converterto heat up more quickly. This reduces emissions quicker. I have read numerous places that removing this causes zero effects on performance. But, I have also read that if this is dirty it will cause idle problems. I don't know if there any other negative effects of a dirty AIV.

I want to remove mine but I don't want to crimp tubing or weld up the hole. I'm moving to another state that has tougher emmissions standards and I may have to reinstall it.I guess this weekend I'm gonna remove it, plug up the whole with Double Bubble Chewing Gum and go to the hardware store to see if I can find a plug. I'd try Wrigleys Spearmint but I heard Double Bubble hardens quicker....Seriously..If I can find a plug...I'll post it here and where to find it.

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

nismo240 wrote:all you have to do is take the pipe coming from your exhaust and take it to a place where they weld and have someone weld up the hole....it is that easy...you can pay $5 in stead of $20 buck for a plug at the dealership! your welcome

Thats the point though, to help clear out my engine bay somewhat. I have dual electric fans, custom intake, battery moved to the trunk. Right now that tube is still on the exhaust side capped off with a bottle cap and electrical tape. I rather have a $2 bolt blocking the hole at the header itself.

Post by **ricebike** » Thu Nov 07, 2002 8:27 pm

just disconnect that rubber hose to the intake box & put a little breather filter on it... from any auto parts store.

that way, it won't be a problem if you want to separate the AIV system from the air intake system. If the AIV reed valves fail & starts spitting exhaust/water back, it won't rust the sensitive MAF meter which is close to the main air filter.

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

I went to ACE hardware and they didnt have anything, and neither did Home Depot. So what i did was take the stock fitting and cut the piping. I left like an 1" sticking out from the nut and I put a rubber cap on it with a hose clamp.

Post by **Redfastbk** » Thu Nov 07, 2002 8:27 pm

I have a 1990 hatch, manual trans, and i also am having trouble with the idle, where would the AIV be located in my car n what would it look like. is the AIV also known as IAA?:slap

Post by **ricebike** » Thu Nov 07, 2002 8:27 pm

AIV is different from IAA

AIV is on the d/s area near your exhaust manifold. mounted near the strut... see a hose coming out ouf the air intake box? then to a black plastic square box? & finally to the AIV...http://wwwcgi.umr.edu/cgi-bin/...t=img

this is a pic of a DOHC engine bay but you can see the red hose coming off the intake tube to that square box... follow it down to the metal AIV

http://www.240sx.org/faq/index.html AIV servicing

IAA idle air adjusting unit has AAC auxiliary air control, FICD and the idle adjusting screw... you'll see that thing buried behind that intake collector w/ that ECCS lettering on it. next to the egr valve...

Ask for FSM page EF & EC 7 for more info... gotta get my other pc up n running to help u out more but others should have a scanner.

Post by **Redfastbk** » Thu Nov 07, 2002 8:27 pm

hey thanks a lot ricebike really appreciate it!

Post by **91nis240** » Thu Nov 07, 2002 8:27 pm

i need to plug the AIV hole up on my hotshot header!!! i cant find anything!!

Post by **Redfastbk** » Thu Nov 07, 2002 8:27 pm

hey RICEBIKE or anybody for this matter, if you can post some pics of the IAA to know what the heck it looks like, i looked behind the ECCS and there is this thing that looks like a typical UFO flying saucer, or the head of the USS Enterprise, would that be it? like i said pics would be very helpful, thanx

Post by **ricebike** » Thu Nov 07, 2002 8:27 pm

like i said my newer pc w/ win 98 had a hard drive crash... still waiting for my bro to diagnose/replace the hard drive fo me so I can finally use my usb-scanner to help out the community :P

Soo rite now, i'm just flexin my fingers to distract me from that stoopid war...

that USS Enterprise seems like the EGR valve or looks like the BPT valve, that disc in plain sight that's in between the valve cover n air collector, near the firewall... someone else would hopefully has a pic of the FSM

Post by **ricebike** » Thu Nov 07, 2002 8:27 pm

91nis, hehe i've seen some people @ the original list where I used to be a part of... someone used a nickel or some coin to weld it shut... hehehe...

i dunno if it's still there in the archives. http://www.amarok.org/htdig/search.html

Re: Fatman Racing out of business? - looking for EGR & AIV plugs...

At 03:23 PM 9/11/01 -0400, David Huguet wrote:>>I tried calling them about the EGR and AIV kits they sell and didn't getan answer - I think it said that the number was disconnected or something.>>I'm about to install a Hotshot header and need to know what type of plugsI can use to block off the EGR and AIV holes - and where to get them.>>Anyone know?>Dave

To my knowledge no. He was about to get married and was working two jobs.Quite a bit of stress for time on him. He was supposed to bring thesite/number back up when he could.

soo the guy just welded a coin! dayum i forgot where the pic was. sorry

Post by **Nismo1182** » Thu Nov 07, 2002 8:27 pm

Redfastbk wrote:hey RICEBIKE or anybody for this matter, if you can post some pics of the IAA to know what the heck it looks like, i looked behind the ECCS and there is this thing that looks like a typical UFO flying saucer, or the head of the USS Enterprise, would that be it? like i said pics would be very helpful, thanx

Theres 2 flying saucer things, one is egr and the one on top im not sure what it is. on the back of the manifold near the egr valve you will see the IAA adjustmenst screw, you have to stand on the passenger side of the car facing the engine.

Post by **240fan** » Thu Nov 07, 2002 8:27 pm

heres what I did, put a rubber cap on the air box and stuck a generic Pcv filter on a shortened piece of hose on the AIV, so it still works if it wants to, but the engine doesnt breathe any exhaust if the thing malfunctions. the AIV is only supposed to open when there is a vacum in the cat, so catalytic action continues thats all an Aiv does.

Post by **Rownan** » Thu Nov 07, 2002 8:27 pm

Redfastbk wrote:hey RICEBIKE or anybody for this matter, if you can post some pics of the IAA to know what the heck it looks like, i looked behind the ECCS and there is this thing that looks like a typical UFO flying saucer, or the head of the USS Enterprise, would that be it? like i said pics would be very helpful, thanx

That would be the EGR valve, which recurculates exhaust gases back into intake system. The IAA should be in front of that, I believe, crammed behind the intake manifold.

Location and Cleaning of AIV

Location and Cleaning of AIV

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