# Idle Problems



## wenwind (Jun 17, 2004)

I have a 1997 Nissan Sentra, Just recently when I slow don or stop with the AC on the engine cuts off. In addition if i'm at idle the engine will cut off. If I turn the AC off the engine runs fine. Does anyone know what could be causing this? Thanks Wenwind


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## azkicker0027 (May 31, 2002)

so you're saying that the car stalls with the AC on?? common cause is a faulty idle air control valve. does the rpm dip very low when coming to a stop, then die??


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## BryanC 95SE-R (Mar 24, 2004)

yeah, it doeson mine too.
bryan


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## webninja (Oct 15, 2002)

It's probably the Air Regulator which is below the IACV. It's a square with two adaptors for hoses on each side, with the square part in the middle. I am pretty sure that the Air Regulator controls (raises) the idle when the AC or other heavy loads are on.


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## payk (May 5, 2004)

*use wd 40*

this was told to me by a nissan engineer not a mechanic but an engineer

there is a sensor on the throttle body held by two scews if you are in front of the car it is right in the middle the screws are facing the firewall
it is right on top on the TB close to the plastic intake 
anyways take it out unplug the harness that it is attached to then just use wd 40 on it , i usually wd 40 the hole too
dry it up then put it back idle should be good as new
been doing it a while and it works...i've done it 4-5 times already 
car has 189k miles


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## Nostrodomas (Jun 15, 2002)

I had the same problem a few years back. I cleaned the IAC valve, and the problem was gone. Still no problems to date.
This is the IAC valve in Red:


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## jeffdano (Aug 8, 2003)

Nostrodomas said:


> I had the same problem a few years back. I cleaned the IAC valve, and the problem was gone. Still no problems to date.
> This is the IAC valve in Red:



Yes, it is 99% likely to be the IAC, this was recommended to me a few months ago (believe I owe thanks to Nostrodomas). You could, if you have the patience, do it yourself, very easy to do with some carb cleaner and a lint-free rag. Haven't had a stall out or issue with AC all summer... thank God because I'm in the freakin' desert!  

-jeffdano


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## Nostrodomas (Jun 15, 2002)

Good to hear it fixed your problem Jeff...


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## 96sentraGL (Jul 19, 2004)

I had this same thing happen to me and I had to replace the idle control valve...


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## pksjay (Oct 27, 2002)

I have a 1996 sentra with 90 k in mileage.

Over the past couple of months i have noticed an extremely rough idle on cold starts. Once the car is running it is fine as well as starting after it is warmed up. 
I plan on replacing the fuel filter this week, is this a sign of an O2 sesor on its way out? 

What else might cause this? Plugs and wires were just replaced..

Thanks for your help


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## Nostrodomas (Jun 15, 2002)

jeffdano said:


> Yes, it is 99% likely to be the IAC, this was recommended to me a few months ago (believe I owe thanks to Nostrodomas). You could, if you have the patience, do it yourself, very easy to do with some carb cleaner and a lint-free rag. Haven't had a stall out or issue with AC all summer... thank God because I'm in the freakin' desert!
> 
> -jeffdano


 :thumbup:


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## pksjay (Oct 27, 2002)

Nostrodomas said:


> :thumbup:


The iac is the thing covered in the black plastic correct? When i unbolt that is it going to fly apart or is it fairly easy to take off and then put back on?


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## Nostrodomas (Jun 15, 2002)

Yes, all you need to do is unplug the sensor. Then take a large phillips screwdriver, and remove the two screws that thread into the throttle body. Nothing is going to fall apart. You do want to go easy on the gasket, if your gentle enough you can reuse it.
Once you get it off, the sensor looks like two cylinders, one inside of each other. The outer one turns, to reveal an opening in the two cylinders. What you want to do is, get some thinner, or gas, brakeclean, and clean the two cylinders. Especially where the slot is made when turning the outer cylinder. Damnitt im getting tired of typing cylinder........lol


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## pksjay (Oct 27, 2002)

Ill give that a try next. I just replaced the O2 sensor, PCV, Plugs, Wires, Dist cap, and Battery. Good old refresher so we shall see.


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## thisisjh (Jul 30, 2004)

*pcv valve.. ground wire.. fuel pressure check*



wenwind said:


> I have a 1997 Nissan Sentra, Just recently when I slow don or stop with the AC on the engine cuts off. In addition if i'm at idle the engine will cut off. If I turn the AC off the engine runs fine. Does anyone know what could be causing this? Thanks Wenwind


You can try to replace your pcv valve.. check ground wires.. and also check fuel pressure... and fuel filter


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## gttech451 (Aug 11, 2011)

jeffdano said:


> Yes, it is 99% likely to be the IAC, this was recommended to me a few months ago (believe I owe thanks to Nostrodomas). You could, if you have the patience, do it yourself, very easy to do with some carb cleaner and a lint-free rag. Haven't had a stall out or issue with AC all summer... thank God because I'm in the freakin' desert!
> 
> -jeffdano


Thanks Nostrodomas, my 1997 200sx (2 door Sentra) w/1.6L had idle problem with or without the AC on, pulled IAC and sprayed with card cleaner and at first no change but moved car an hour later and runs good, this condition triggered the check engine light and OBD tool gave code 100 and said MAF & VAF but cleaning IAC cured and no engine light yet, hope this helps other Sentra/200sx owners, thanks to all posters Grant. also the picture really helped.


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