4th Generation Maxima (1995-1999) Visit the 4th Generation forum to ask specific questions or find out more about the 4th Generation Maxima.

High unstable idle after cleaning IAC

Thread Tools
 
Search this Thread
 
Old 04-10-2007, 05:59 PM
  #1  
Yahhhhhhh
Thread Starter
iTrader: (9)
 
Majestic's Avatar
 
Join Date: Jul 2005
Location: Baltimore, MD
Posts: 2,855
High unstable idle after cleaning IAC

I cleaned my IAC valve yesterday with some throttle body cleaner. I just removed it and hit it with a tooth brush and sprayed some down the tube also. Now my idle is high (1000rpm) and it bounces slightly but not much. Is this normal or did I jack something up? I cleaned my throttle body at the same time also.
Majestic is offline  
Old 04-10-2007, 06:19 PM
  #2  
Member
 
evildoughboi's Avatar
 
Join Date: Jul 2005
Posts: 52
make sure you tightened that valve; i didnt and the car stalled after it successfully started (rpm dropped and continued to do so). also check that the gasket is in ok condition. you might want to replace it since your there anyway.

i kind of have the same problem. the car drives ok but the idle bounces around (from 900 in drive to about 600 - pretty bad, almost stalls at 600) after i replaced the injectors. i tried tweaking the TPS both times and it kind of fixed it temporarily. try turning that screw on the AAC motor to adjust the idle rpm.

im hopefully it'll work itself out for my car.
evildoughboi is offline  
Old 04-10-2007, 06:28 PM
  #3  
Yahhhhhhh
Thread Starter
iTrader: (9)
 
Majestic's Avatar
 
Join Date: Jul 2005
Location: Baltimore, MD
Posts: 2,855
Well It's not bouncing down low at all. Really you'd have to be staring at it to even see it moving so it's not that bad. I can't remember where you adjust the idle. I think that may just solve my problem. I hope your problem gets worked out as well.
Majestic is offline  
Old 04-10-2007, 06:47 PM
  #4  
Senior Member
iTrader: (1)
 
heynow's Avatar
 
Join Date: Aug 2006
Posts: 1,132
black plastic screw on the IACV can be used to adjust the idle
heynow is offline  
Old 04-10-2007, 06:55 PM
  #5  
Senior Member
 
killerVQ30DE's Avatar
 
Join Date: Jan 2005
Posts: 1,108
Not same prob as you guys but.. I had real low idle at startup and stalling, etc and had to up the IACV valve to bring revs up by 300.. cleaned my TB and boom starts no problems .. lowered rpms back down to 700rpm



killerVQ30DE is offline  
Old 04-10-2007, 07:10 PM
  #6  
Yahhhhhhh
Thread Starter
iTrader: (9)
 
Majestic's Avatar
 
Join Date: Jul 2005
Location: Baltimore, MD
Posts: 2,855
Originally Posted by heynow
black plastic screw on the IACV can be used to adjust the idle
Black plastic screw?
Majestic is offline  
Old 04-10-2007, 07:11 PM
  #7  
Yahhhhhhh
Thread Starter
iTrader: (9)
 
Majestic's Avatar
 
Join Date: Jul 2005
Location: Baltimore, MD
Posts: 2,855
Originally Posted by killerVQ30DE
Not same prob as you guys but.. I had real low idle at startup and stalling, etc and had to up the IACV valve to bring revs up by 300.. cleaned my TB and boom starts no problems .. lowered rpms back down to 700rpm



That's a really dirty TB.
Majestic is offline  
Old 04-10-2007, 10:07 PM
  #8  
Senior Member
iTrader: (7)
 
Cdg2125's Avatar
 
Join Date: May 2004
Location: CT
Posts: 4,640
ok....the black plastic screw is the Idle Air screw. You can turn that to adjust your idle. As should be expected, after cleaning your IACV the idle will increase. Think about it...lots of dirt slows air. Once it's cleaned air can move in better and rpms will increase. Give it time, your car should adjust and drop the idle. If not in a week or so then adjust the Idle Air screw.
Cdg2125 is offline  
Old 04-10-2007, 10:35 PM
  #9  
Senior Member
 
andrei3333's Avatar
 
Join Date: Nov 2006
Posts: 2,391
the same thing happend to my old buick when i washed the engine, for 2 days idle was high then just dropped to normal

i plan to take off my tb and iacv to clean them in the near future and expect the idle to rise, just adjust to the oem spec 700 no load idle rpm.
andrei3333 is offline  
Old 04-10-2007, 10:38 PM
  #10  
Member
iTrader: (1)
 
mikejw22's Avatar
 
Join Date: Feb 2007
Posts: 55
Did you use replace the old gaskets with new ones after the cleaning???
mikejw22 is offline  
Old 04-11-2007, 05:03 AM
  #11  
Yahhhhhhh
Thread Starter
iTrader: (9)
 
Majestic's Avatar
 
Join Date: Jul 2005
Location: Baltimore, MD
Posts: 2,855
I kept the gasket but it was fine. I'm going to give it a couple days though.
Majestic is offline  
Old 06-06-2007, 01:13 PM
  #12  
Senior Member
 
andrei3333's Avatar
 
Join Date: Nov 2006
Posts: 2,391
so hows the idle ? did it come down or u adjusted it ? im about to do this on the weekend
andrei3333 is offline  
Old 06-06-2007, 01:54 PM
  #13  
Yahhhhhhh
Thread Starter
iTrader: (9)
 
Majestic's Avatar
 
Join Date: Jul 2005
Location: Baltimore, MD
Posts: 2,855
Came down to 700 so now it's normal. It was normal about a week or two after this thread.
Majestic is offline  
Old 06-06-2007, 04:10 PM
  #14  
Senior Member
 
Love_00_Max's Avatar
 
Join Date: Oct 2003
Location: Pleasanton,CA
Posts: 1,136
Curious to know, why do you even clean the IAC. Does it get as dirty as the TB and what are the symptoms of a clean necessary?

I clean the TB, once in a year when there is this occasional jerk at low speeds (kind of odd feeling) and when I get to the TB, it actually is dirty but not as one of the above pictures.
Love_00_Max is offline  
Old 06-06-2007, 04:16 PM
  #15  
Senior Member
iTrader: (2)
 
f550maranello2's Avatar
 
Join Date: Jun 2004
Posts: 3,499
DID ya see the pics above?
f550maranello2 is offline  
Old 06-06-2007, 04:24 PM
  #16  
Senior Member
 
Love_00_Max's Avatar
 
Join Date: Oct 2003
Location: Pleasanton,CA
Posts: 1,136
Originally Posted by f550maranello2
DID ya see the pics above?
Are u referring to the TB pictures, wow it looks pretty dirty?

I don't disassemble while cleaning mine, turn the butterfly plate over and clean the back side.
Love_00_Max is offline  
Old 06-06-2007, 09:03 PM
  #17  
Senior Member
 
andrei3333's Avatar
 
Join Date: Nov 2006
Posts: 2,391
if u have idle other then 700 at no load it could be due to a dirty iac valve, it restricts proper airflow to the point where the ecu can no longer compensate for it. also a jumpy idle could be a symptom of a dirty iacv

my idle is at 700 hot no load in P, but as soon as i switch to D it goes to 550 and stays there
andrei3333 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
BkGreen97
Maximas for Sale / Wanted
2
04-02-2016 05:47 AM
97_GXE
4th Generation Maxima (1995-1999)
20
09-17-2015 08:12 PM
seesole
7th Generation Maxima (2009-2015)
15
09-14-2015 12:38 PM
NissanNismoZ
6th Generation Maxima (2004-2008)
4
09-12-2015 07:30 AM
sdotcarter
6th Generation Maxima (2004-2008)
2
09-02-2015 09:53 PM



Quick Reply: High unstable idle after cleaning IAC



All times are GMT -7. The time now is 12:41 PM.