AIV Repair/Removal, sticky?

Post by **Redline240** » Sun Jun 22, 2003 9:05 am

Ok anyone know what might cause rough idle on a S14? I started reading this thread hoping it was my solution, then i realized removing something that isn't there won't help, lol...

Redline

Post by **EastCoast240** » Sun Jun 22, 2003 9:05 am

Just removed mine. Engine bay looks much cleaner. Idle is now a little higher at approx 850rpm.

pOOt, have you removed your charcol canister as well? Did your idle go up?

Post by **p00t** » Sun Jun 22, 2003 9:05 am

my idle leveled out at its proper 700rpm idle level and is smoother. under braking if it bogs it will never dip below 600rpm, never stall out.

the charcoal canister just holds gas tank vapor, the only reason to service/remove it is if the valve on it goes south. i believe that is rare.

how many miles are on your car? and what was the idle doing before? if it has high miles and had previous owners they may have adjusted the idle alittle bit(if it was too low or stalling). if the idle doesnt settle at 700 then just use the idle adjustment screw to move it down.

Post by **NISTECH** » Sun Jun 22, 2003 9:05 am

here in calif. no matter how clean of a job you do if the under hood label says it has air. or if the label is missing and the technicians refrence book says it has air. if he sees its not their you will fail the visual inspection part of the smog. in some cases you may get a technician that is not very thorough when performing a smog check it may slip by . but with the fines we are threatened with by the BAR alot of us dont miss this stuff anymore. it would be best to rig it up so it can be reinstalled for the emissions test when due.

Post by **240SXer** » Sun Jun 22, 2003 9:05 am

Yeah.. We all know that it's not CARB legal. But smog only comes every 2 years, and it's pretty easy to replace. I'm very familiar with visual inspections, however, there is a GOOD chance that if you did a good job, they won't notice, unless for some reason they're going crazy with the inspection on your car.

Post by **powerdrifter** » Sun Jun 22, 2003 9:05 am

If your exhaust is shooting lots of black soot around your rear bumper, or if your top-end sucks, a reed in the AIV Valve is broken. If you fail emissions due to very high hydrocarbons, it's the AIV Valve as well. I was told by someone at the Nissan Motorsports office in Gardena, CA that, yes the AIV valve is pointless, but when you begin to modify the car or bolt on a Performance exhaust, it will keep your car from backfiring. Remember people, we're going for clean, factory-look installations here. If you have to eliminate it, use break cleaner to clean it up inside after opening the two halves, then just bend the metal valves up so the reeds don't move at all(a bit of copper silicone gasket stuff should also help). This all makes sense when you take it apart (for those who have not done this yet). TRUE JDM DRIFTING STYLE IS ABOUT A CLEAN INSTALLATION!

Post by **~*IdIoT bOx*~** » Sun Jun 22, 2003 9:05 am

240SXer wrote:Yeah.. We all know that it's not CARB legal. But smog only comes every 2 years, and it's pretty easy to replace. I'm very familiar with visual inspections, however, there is a GOOD chance that if you did a good job, they won't notice, unless for some reason they're going crazy with the inspection on your car.

u wouldn't happen to have some pics of the inside of the AIV valve? i dunno wut i'm looking at or hafta clean....i started another thread on AIV cleaning but noone has responded...

Thanks

Post by **powerdrifter** » Sun Jun 22, 2003 9:05 am

You don't need pics. It really is that easy. you just need a 10mm deep socket and maybe a short ratchet extension, and either a srewdriver with a good grip or an impact driver to remove to the phillip screws that hold the cover together (gasket gets a good grip when heated in normal use). Once it's open, it all makes sense.

Post by **~*IdIoT bOx*~** » Sun Jun 22, 2003 9:05 am

so the cover is the circular part on the top right? and i'll find the reeds inside. SO i dun even need to take it out of the car i guess cause its really easy to get too. Thanks for ur help!

Post by **powerdrifter** » Sun Jun 22, 2003 9:05 am

Hold on there. The round part on top with the small bracket going over it is only the plunger which is activated by a solenoid and vaccum hose. That round plunger is on the top half of the AIV valve, the actual piece you want to open up is the aluminum housing on it. Coming off the exhaust is that metal snake pipe (@1/2" diam.) which goes into a rubber hose, with goes into the bottom of the aluminum housing. You have to disconnet the vacuum hose coming from the air filter to the black box by the ignition coil. That black box is connected with a short rubber hose to the other half of the AIV Valve. It is extremely easy to do. I do it about once every three months to check the reeds and clean it out. (I drive my 240sx very hard so I do more maintenance than normal to keep the car in good shape.) You know, it's funny. My wife never understood "all the crap I was doing to the car", until my work schedule changed to include O.T. So she was taking the car, dropping me off and picking me up. I guess driving by herself, having others try to race her on the freeway, she started to drive the car hard and know realizes what a difference I've done when compared to my brothers 240SX's (they each have stock ones as well). Hard driving=more maintenance! ENJOY THE RIDE...

JDM is the true path to performance!

[email protected]'89 NISSAN 240SX, '90 KA24E SOHC,5-spd conversion,'96 180sx turbo fuel pump,port & polished:head (in/exh), MAF sensor (main inlet only), air filter adapter, throttle body, intake plenum, intake manifold, removed SCV valves (2nd butterflies) Injen intake, HKS SuperMega Flow Filter, HotShot Headers (w/ thermotec exh. wrap to cat-back exh. canister), custom 60mm straight exhaust (JDM), HKS Superlow Form Springs, KYB AGX shocks (adj.4/8), FR/RR strut bars, Nismo Chassis brace, Random Tech High Flow cat., HyperGround Wire System, Magnecor 8.5mm wires, Splitfire 3xPlatinum plugs, Nismo Radiator Cap (18psi/1.3bar), S13 VLSD, ENDLESS brake pads, Jun Lightweight Flywheel, Centerforce Dual Friction clutch,Optima Battery, Bomex body kit, about to be the 1st, FIRST! in the US with a JDM Ikeya Formula Complete body kit...

Post by **~*IdIoT bOx*~** » Sun Jun 22, 2003 9:05 am

Thanks for all the help!

Website · Post by **lbrowne** » Sun Jun 22, 2003 9:05 am

you think a AA battery is safe to jam into the pipe coming from the exhaust? If that heater hose was on there it shouldn't get too hot...

what do ya think? This shiat took me like 10 minutes to rip out.

Post by **powerdrifter** » Sun Jun 22, 2003 9:05 am

I think you really don't know how much damage that battery can do. The moment your car is up to normal operating temperature, that battery is going to pop! It has a slow acting alkaline acid inside which, if you don't care about you're headers, should be fine. But once it blows it won't seal up anymore so you're back to square 1.

Try the advice I gave above and bend all the reeds up. If you haven't cleaned out the AIV Valve, spend an afternoon with friends to do it together. It's the best way to spend the weekend.

Website · Post by **lbrowne** » Sun Jun 22, 2003 9:05 am

Oh its all done, I've long changed my mind about using the battery once common sense kicked in about the heat it would be exposed to. I placed a bottle on the end with high temp RTV sealant, then wrapped it extensively with duct tape after. I think it'll be safe.

All the lil rubber tubes I bent/kinked, plugged the ends and taped them, then at each kink I placed a zip tie pulled real tight, those fuqers ain't leaking

Post by **p00t** » Sun Jun 22, 2003 9:05 am

OK guys i got the car inspected recently here in NJ with the AIV removed, passed with flying colors. everything was real good, except my NOx was 1033, failing was 1045 that was the worst, everything else passed perfectly!

Post by **allens 240sx** » Sun Jun 22, 2003 9:05 am

so break cleaner would or wouldn't work for cleaning it out... or is there something better to use.??

Post by **Touchdown038** » Sun Jun 22, 2003 9:05 am

So what exactly is this mod supposed to do? Give you a smoother idle and a little bit more power?

Post by **p00t** » Sun Jun 22, 2003 9:05 am

allens 240sx wrote:so break cleaner would or wouldn't work for cleaning it out... or is there something better to use.??

carb/brake cleaner or gasoline are perfect for cleaning the crud off of the reed valves. its similar to the gunk you find on your throttle butterfly plate.

Touchdown038 wrote:So what exactly is this mod supposed to do? Give you a smoother idle and a little bit more power?

depends... if you are having idle/power problems it is a good place to start. typically this is for the stalling under braking or unstable idle crowd.

Post by **powerdrifter** » Sun Jun 22, 2003 9:05 am

The idea behind removing the AIV Valve on a 240SX is that it DEFINETELY INCREASE YOUR TOP END! When you start noticing the black soot that comes out of the exhaust and covers you rear bumper with it or when your top end just sucks, that's the AIV Valve. Fix the valve and the black stuff is gone!

When you have this problem, burnt fuel mixture that is no longer usable gets recycled through the AIV Valve, back into the intake, through the combustion process, and since some of that bad air is no longer usable, it raises your NOX levels sky high. You can either fix the reeds, rig them so they don't work at all, or simply remove them.

Post by **Chingon** » Sun Jun 22, 2003 9:05 am

my brother removed this and covered the holes like you instructed poot but the car still stalls, like when you first turn it on, if you don't get the car moving the rpms will drop and the car will stall.

Post by **Touchdown038** » Sun Jun 22, 2003 9:05 am

You must have a vacuum leak through one or more of the lines then. If it works with the AIV, and you plug the lines, the vacuum doesn't change, so it should work.

Post by **Chingon** » Sun Jun 22, 2003 9:05 am

what? Im an absolute newbee.

Post by **Touchdown038** » Sun Jun 22, 2003 9:05 am

Ok... your engine has vacuum at all times. And the two hoses you plug as part of the removal are vacuum tubes (actually, I think just one of them is, correct me if I'm wrong.) And unless they are completely plugged, the engine will suck in air and the vacuum will go away. So you need to completely plug them or else the engine will stall, or run like crap.

Post by **powerdrifter** » Sun Jun 22, 2003 9:05 am

Easiest way to plug them is to simply bend the hose and put a zip tie to hold it on. This won't work if you have old vacuum hoses. You'll just end up breaking them in half. You could also stick a bolt or screw in the hose with silicone on the threads to seal it up better. If the problem continues, you got a leak somewhere else or a different problem.

Post by **Chingon** » Sun Jun 22, 2003 9:05 am

I just checked and the two hoses that remained from the removal of the AIV are well sealed, no air going in trought them. I'll try to describe my problem: my car works perfectly fine sometimes, but a lot of times when I turn it on the rpms drop until it stalls, the way to get out of this situation is to get moving before the car stalls. Yesterday was the exeption however when I first turned on the car in the morning, I was having this same problem really bad and it wouldn't go away but I drove it anyways, throttle response was way off, I had my foot all the way down on the accelerator on like second gear doing about 15mph, the rpm needle would struggle to go up, it would have little burst of rpm gains and then move up very slowly or not at all again, when I suddenly let go of the gas it would actually have a very small burst of speed which I taught was pretty weird and I had never had before.What do you guys think?

Post by **Touchdown038** » Sun Jun 22, 2003 9:05 am

I take it this problem started happening before you did this mod...

Sounds like a fuel problem to me. Anybody else second that?

Post by **GroundZero** » Sun Jun 22, 2003 9:05 am

how old is your catalytic converter on your car? if it's clogged it could be your problem, too much backpressure can cause MASSIVE power losses, stalling, hardstarting, low or no idle, etc... just for ****s and giggles unbolt the catalytic from you headers, move it out of the way and then see how the car runs. i performed this test twice before (on my Cutlass and my RX-7 that i used to have) in both instances the converter was the culprit. if so then buy a new one or do what i would do- 1) remove cat 2) find a piece of pipe 3) use pipe to gut the piss out of the converter 4) reinstall ghetto test pipe and enjoy.

Post by **Chingon** » Sun Jun 22, 2003 9:05 am

That's a good suggestion...however, do I have to remove the headers? If so, do I have to torque these to certain specs? How loud will the car be if I remove the catalytic to test? By the way, I think my cat is the same that came out of the factory...1991, 150k miles.

Post by **GroundZero** » Sun Jun 22, 2003 9:05 am

no you do NOT remove the headers. all you have to do is unbolt the catalytic where it meets the headers, pull the converter out of the way so that it isn't blocking the output of the exhaust coming from the headers. what i did to hold it out of the way was to use one of the bolts to connect the left bolt hole of the converter to the right bolt hole of the headers. when you have it setup to where the headers have a clear shot into the atmosphere then crank her up, give the car a test drive around the block and cherish the looks you get from your neighbors, if the car hauls *** then the catalytic is your problem if it still has the problem then let us know, i doubt that any of us like the idea of a dying nissan. good luck

Post by **Chingon** » Sun Jun 22, 2003 9:05 am

well I just sealed all of the hoses with silicon like power driftter suggested and it didn't stall, but like I said sometimes it works just fine so I will wait and try it with the engine cold a couple more times.When it fails it does feel like something is clogged so the catalytic might be it ground zero.

AIV Repair/Removal, sticky?

AIV Valve gremlins?

ok, so for cleaning the AIV...

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