# Cold Idle Speed



## Teneye (Oct 10, 2005)

I'm new to these forums and I'm looking for some advice.

I have a new to me 1990 Stanza with 51,000 mi and clean! I have done most of the maintenance i.e. plugs,wire,cap,rotor, oil etc. On cold start-up I have to feather the gas pedal to keep the car running. Also once warm it idles fine in neutral or park. When I turn on the a/c the idle drops and runs rough. At traffic lights the car will idle somewhat rough but when the car is put in neutral at the light it purrs like a kitten. I'm thinking this must be some type of sensor. I've put about 300 mi on the plugs and then pulled them to have a look and see how they performed but one plug seemed to have too much carbon for the 300 miles. I've searched the forums and didn't see this specific problem addressed.

Thanks in advance for any suggestions!


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## DRUNKHORSE (Mar 6, 2005)

first check the IDLE SPEED CONTROL ACTUATOR then the TPS, if those dont wokr then maybe the IDLE STOP SOLENOID or the IDLE AIR CONTROL VALVE. If still nothing happens then ur EGR valve or PCV. have u changed ur fuel filter?


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## Teneye (Oct 10, 2005)

Thanks for the quick reply!

Today I'm going to change the fuel filter and replace the belts (belts as pm not a solution) . EGR seems to work OK but I can only test it by pushing it up by hand and the car stalls.

Unfortunately, I have no idea how to test the sensors mentioned and I do not have the tools. I'm hoping some of the systems will loosen up with more use. For example, shifter will now work when I appy the brake instead of having to use the release button, the car sat quite a bit. Again, I'm going to replace the fuel filter and pcv today hopefully I'll see some improvement- we'll see. Thanks!


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## isb360 (Apr 6, 2005)

maybe a vacuum leak?


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## Teneye (Oct 10, 2005)

I have replaced the fuel filter and pcv valve and the car still idles too low. I have visually inspected the vaccuum hoses and I can't see any cracks.

Other that this low idle issue, the car is running excellent! This 2.4l motor really gets this car moving.


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## DRUNKHORSE (Mar 6, 2005)

Teneye said:


> I have replaced the fuel filter and pcv valve and the car still idles too low. I have visually inspected the vaccuum hoses and I can't see any cracks.
> 
> Other that this low idle issue, the car is running excellent! This 2.4l motor really gets this car moving.


Im gonna guess that it's the Idle Air Control Valve, my best guess, and if its not that then it will be the Idle Speed Actuator, but moslikely its the IACV. I singled them out cause I dont think its gonna be the TPS.
http://autozone.com/servlet/UiBroke..._us/0900823d/80/04/b2/f6/0900823d8004b2f6.jsp knowing the definition of the IACV helps to single out the problem. If u want more definitions of other sensor or just about anything click the " Products and how to info".


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## Teneye (Oct 10, 2005)

Thanks for the link.

First chance I get I think I'll pull the valve and see if can be cleaned up. If not, it's good to see that I can get the part at the local AZ.


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## Teneye (Oct 10, 2005)

I finally got around to ordering and replacing the IACV. Problem solved!
Thanks for the help!


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## phin (Jul 20, 2005)

Teneye said:


> I finally got around to ordering and replacing the IACV. Problem solved!
> Thanks for the help!


Where is the IACV valve situated?. How much does it cost ? .I think i
may have the same problem. Thanks.


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## Macc (Jul 4, 2005)

The IAC is on the opposite end of the plenum from the throttle body. At the auto stores it costs around $100. Try cleaning it and the electrical connections first.


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## Teneye (Oct 10, 2005)

Sorry for the late reply.
The best price I could find was at Auto Zone. The part had to be ordered but it only took one day. http://autozone.com/servlet/UiBroke...23d8004b2f6.jsp
The install took me about 2 hours because I also replaced some vaccuum lines.


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## stanzadriver90 (Nov 15, 2005)

Does this actually fix it?? i am having the exact same problem with my 90 stanza and i couldn't figure out what it was bcause i already replaced all the vacuum hoses and tightened up the throttle cable and it just goes back to how it was....i'll keep you all posted on how it works for me


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## phin (Jul 20, 2005)

Macc said:


> The IAC is on the opposite end of the plenum from the throttle body. At the auto stores it costs around $100. Try cleaning it and the electrical connections first.


hi , Is the IAC the same as the AAV ?.I have a 91 stanza and at the opposite
of the throttle body is located the PCV and opposite to it is the AAV. Is that
what we are talking about?.I've been quoted $200-$300 at the auto stores.

Thanks


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## Macc (Jul 4, 2005)

The idle controller is often called many different names by the various car manufacturers. For your year Stanza in some of the repair books (Chilton's) they call it the IAA. If you go to some of the autostore websites (say autozone) they call it the Idle air control valve (IAC). Either way, that is it just to the left (and downward) of the PCV valve. It is attached by 4 bolts. Underneath it is a hose (roughly 3/4") that brings the air to it. Attached to it (to the left) is the goldish colored electric motor that controls it (you will see the electrical connection to it). Often the IAC valve will stick and cause the problem as described. I would recommend removing and cleaning it with something like carburator cleaner first (might save you some $$$). Then after you reassemble everything you need to take the car for a good drive (several miles) at a moderate speed (35 mph or more) so that the computer can readjust and learn its steps. Note; during this time it might run kind of rough but it will clear up. Good Luck!


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## Stanza92MP (Dec 9, 2005)

Teneye said:


> I'm new to these forums and I'm looking for some advice.
> 
> I have a new to me 1990 Stanza with 51,000 mi and clean! I have done most of the maintenance i.e. plugs,wire,cap,rotor, oil etc. On cold start-up I have to feather the gas pedal to keep the car running. Also once warm it idles fine in neutral or park. When I turn on the a/c the idle drops and runs rough. At traffic lights the car will idle somewhat rough but when the car is put in neutral at the light it purrs like a kitten. I'm thinking this must be some type of sensor. I've put about 300 mi on the plugs and then pulled them to have a look and see how they performed but one plug seemed to have too much carbon for the 300 miles. I've searched the forums and didn't see this specific problem addressed.
> 
> Thanks in advance for any suggestions!


I have a 92 Nissan Stanza 218000 km's (canadian) and I seem to be experiencing the same problem.
Basically my problem has become alot more noticable in the cold weather. When I start the car it revs up to about 1.5 rpm then drops dangerously low and flutters and goes up to about 1.5 then repeats... It has only stalled once but indeed it drops dangerously low. I've very minimal knowledge of cars and dont want to take it to a mechanic to be ripped off (I'm a student so $$$ is scarce) Also when I'm using transmission breaks or down shifting the car jerks every couple of seconds like the engine is mis firing. Sometimes the same thing happens when i'm accellerating except it doesn't jerk it just feels like I have no power for a second or so.

Any help would be greatly appreciated Thanks


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