AIV (AIR INTAKE VALVE QUESTION) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Powerzen2002 · 04-08-2002, 06:06 PM

Ok.  Stupid question.  on a '90 240sx where is the AIV?

My car's acceleration is really crap the past week or so...
So, I'm pretty new to Nissan cars ... I went lookin around
and think I got it.  

But, I just wanna make sure bout putting it back properly too... I dont wanna have exhaust back track up to the engine.

thanks,
PowerZen

240sxracer · 04-08-2002, 07:12 PM

ok, if your standing in front of your car look right of the exhast manifold. youll see a little black box. that box has a hose that goes straight down into this metal thing(aiv).
the aiv also has a hose that goes into a pipe that runs into the exhaust. the aiv is easy to take apart i soaked mine in gas (ran out of carb cleaner) cleaned all the carbon out of it.
also on top of the aiv is the (a reed valve)($36)its round or cilinder in shape has a vacum hose that runs into it. youll take that off when you take the aiv apart. mine had rusted out badly and was not working right so check that too. also if you have a aftermarket intake on your car and you have a breather(small filter hooked up to that small black box replace that filter if its dirty.

Powerzen2002 · 04-10-2002, 07:00 PM

OOoh Ok.  Just that  I didnt wanna start taking things apart.  Thanks alot.  What would I have to do if I wanted to replace that with a breather filter?  How would I go about doing that.

I mean....  where would I attach it to?  And how much gain do I get from that?  would it be a very noticable differnce?  Is it benficial?  

Thanks again for your info!

*sykikchimp* · 04-10-2002, 11:25 PM

How would the AIV effect acceleration?  All it does is send air to the exhaust to imrove emmisions?

Sometimes the IAA valve can cause performance issues but those are pretty much strictly limited to idling performance.

S13drift · 04-11-2002, 07:38 AM

Check your vaccum hoses for cracks.

Powerzen2002 · 04-11-2002, 10:20 AM

Could be caused by back-pressure if that air does not flow non restricted.  Just an idea!  However, I cant get the damn AIV apart because the screws became crap after so many years.

Before I bother with this, has anybody had bogging down poor performance issues because of the AIV???

S13drift · 04-11-2002, 10:57 AM

When you were helping me with my problem I took a look at BPT Backpressure Transducer valve.  That is the round thing with the two small hoses going to it at the top and a tad bit larger one at the bottom.  It's almost over injector number 4.  The hose at the bottom of the BPT had cracked and it was causing the bogging down.  It's one place you might want to check

04-08-2002, 06:06 PM	#1
Powerzen2002 Zilvia Member Join Date: Apr 2002 Posts: 225 Trader Rating: (0) Feedback Score: 0 reviews	Ok.  Stupid question.  on a '90 240sx where is the AIV? My car's acceleration is really crap the past week or so... So, I'm pretty new to Nissan cars ... I went lookin around and think I got it.   But, I just wanna make sure bout putting it back properly too... I dont wanna have exhaust back track up to the engine. thanks, PowerZen __________________ No Quote, No Cares, Just Drive.

04-08-2002, 07:12 PM	#2
240sxracer Zilvia Member Join Date: Oct 2001 Posts: 197 Trader Rating: (0) Feedback Score: 0 reviews	ok, if your standing in front of your car look right of the exhast manifold. youll see a little black box. that box has a hose that goes straight down into this metal thing(aiv). the aiv also has a hose that goes into a pipe that runs into the exhaust. the aiv is easy to take apart i soaked mine in gas (ran out of carb cleaner) cleaned all the carbon out of it. also on top of the aiv is the (a reed valve)($36)its round or cilinder in shape has a vacum hose that runs into it. youll take that off when you take the aiv apart. mine had rusted out badly and was not working right so check that too. also if you have a aftermarket intake on your car and you have a breather(small filter hooked up to that small black box replace that filter if its dirty. __________________ 1990 240sx FastBack 1965 Ford F100

04-10-2002, 07:00 PM	#3
Powerzen2002 Zilvia Member Join Date: Apr 2002 Posts: 225 Trader Rating: (0) Feedback Score: 0 reviews	OOoh Ok.  Just that  I didnt wanna start taking things apart.  Thanks alot.  What would I have to do if I wanted to replace that with a breather filter?  How would I go about doing that. I mean....  where would I attach it to?  And how much gain do I get from that?  would it be a very noticable differnce?  Is it benficial?   Thanks again for your info! __________________ No Quote, No Cares, Just Drive.

04-10-2002, 11:25 PM	#4
sykikchimp WOW addicted Join Date: Dec 2001 Location: the moon Age: 44 Posts: 6,525 Trader Rating: (0) Feedback Score: 0 reviews	How would the AIV effect acceleration?  All it does is send air to the exhaust to imrove emmisions? Sometimes the IAA valve can cause performance issues but those are pretty much strictly limited to idling performance. __________________

04-11-2002, 10:20 AM	#6
Powerzen2002 Zilvia Member Join Date: Apr 2002 Posts: 225 Trader Rating: (0) Feedback Score: 0 reviews	Could be caused by back-pressure if that air does not flow non restricted.  Just an idea!  However, I cant get the damn AIV apart because the screws became crap after so many years. Before I bother with this, has anybody had bogging down poor performance issues because of the AIV??? __________________ No Quote, No Cares, Just Drive.

04-11-2002, 07:38 AM	#5
S13drift Leaky Injector Join Date: Feb 2002 Location: Charlotte, NC Age: 47 Posts: 52 Trader Rating: (0) Feedback Score: 0 reviews	Check your vaccum hoses for cracks.

04-11-2002, 10:57 AM	#7
S13drift Leaky Injector Join Date: Feb 2002 Location: Charlotte, NC Age: 47 Posts: 52 Trader Rating: (0) Feedback Score: 0 reviews	When you were helping me with my problem I took a look at BPT Backpressure Transducer valve.  That is the round thing with the two small hoses going to it at the top and a tad bit larger one at the bottom.  It's almost over injector number 4.  The hose at the bottom of the BPT had cracked and it was causing the bogging down.  It's one place you might want to check