# IACV - Iadle Air Contr. Valve - of Nissan Altima



## Zurab (Feb 25, 2020)

I have a starting problem of my Altima 2000. OBDII pulled out P0505 and it is idle air control valve (IACV). I tested wiring to/from this valve - connections, power feed, resistance etc. All look fine. Remains to test if valve’s 'spindle' is stuck and needs to be cleaned.

I did locate it. In difference from other models, it is located at opposite side of the throttle body and seems hard to remove without getting underneath of the car. My question is, for the spindle test and clean up, would be enough to remove just that yellow cylinder?
(see pic from rockauto’s shop:
More Information for WVE 2H1257 ) Remaining looks like just housing.

If this is the case, then the job should be much easier and may be that yellow part would be cheaper to get? [in case replacement needed].


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## Zurab (Feb 25, 2020)

Is there any way to bypass the IACV functioning upon the starting the car? This would be simple way to diagnose IACV. If car will start (with IAC valve bypass), than definitely it needs reparation. Otherwise, there is also another problem.


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## smj999smj (Jan 1, 2006)

There is no way to bypass the valve. Also, the valve is sold as an assembly and pieces of it are not available separately. I known it's a pain, but replace the IACV as an assembly. Once installed, you then have to adjust the base idle per the service manual procedure, which involves warming up the engine, turning it off, disconnecting the TPS, etc.


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## Zurab (Feb 25, 2020)

Many thanks for your replay.
I already done with final exams and today we got sunny day. So I am thinking
to remove IACV with needed effort  [my car is parked outside - basically in the street].



smj999smj said:


> Once installed, you then have to adjust the base idle per the service manual procedure, which involves warming up the engine, turning it off, disconnecting the TPS, etc.


What I learned from some videos, old models' [before 1999] IACV had adjustable screw, which allowed to open/close the valve from outside. But 1999-2001 models' IACV has no such screw outside.
I'll search how this procedure should be done.
But firs I have to remove, clean, test and re-install it.
Will post and share my experience later.


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## Zurab (Feb 25, 2020)

Zurab said:


> old models' [before 1999] IACV had adjustable screw, which allowed to open/close the valve from outside. But 1999-2001 models' IACV has no such screw outside.


I think what I wrote about adjustable screw is not correct.
Today, struggling with the removal, I noticed the hole which probably has
adjustable screw there. Without component whole removal it is hard to say, because
one can not look inside.
I am attaching the e-bay pic, where I marked/located that hole.
Anyone, knowing this, please kindly let me know if this is the hole with adjustable screw inside?
And would opening it, can let air to go inside and help to start the car?
And is it advisable at all to rotate/touch that screw?

p.s. After noting that hole, I decided to not continue and stopped removing.
May be, that hole is for cleaning by spaying there cleaner? That would be nice 
Many thanks.


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## rogoman (Dec 16, 2004)

The IACV for your car is not adjustable; removing the unit and cleaning the inside with a carb cleaner may help; worth a try. That hole is where there's a calibration adjusting screw. After calibration at the factory, the adjustment screw is thread-locked to remain in spec, so I wouldn't mess with it.


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