Engine, Drivetrain & Forced-Induction Have Technical Questions or Done Modifications to the G35? Find out the answer in here! (View All Posts)
Sponsored by:
Sponsored by: CARiD

Low idle when AC is turned off

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Apr 17, 2018 | 03:32 PM
  #1  
yag's Avatar
yag
Thread Starter
|
Registered User
Joined: Apr 2018
Posts: 15
Likes: 1
Low idle when AC is turned off

I know this topic has been done to death but I seriously need help. Ever sense I've owned my 04 g coupe mt it idles consistently at 200rpm when the AC is turned off. With the AC on it idles perfectly at 750rpm. It doesn't throw a check engine light. I know the tachometer can't be off because the car gets very shaky like it's going to stall. I've already done the following to try to fix this:
-Reset ECU
-Clean TB/new TB
-Clean MAF/new MAF
-Check hoses, intake and plenum for leaks
-Accelerator Pedal Released Position Learning
-Throttle Valve Closed Position Learning
-Idle Air Volume Learning
If anyone has any suggestions I would love to hear them.
 
Reply
Old Apr 17, 2018 | 04:34 PM
  #2  
cleric670's Avatar
BANNED!!!
Joined: May 2017
Posts: 14,837
Likes: 2,497
From: Washington State
Coupe 6MT Premium RAS
Premier Member

Do the idle air volume again, did you make sure the engine was up to operating temp when you did it and that the AC was turned OFF ?
 
Reply
Old Apr 17, 2018 | 04:48 PM
  #3  
yag's Avatar
yag
Thread Starter
|
Registered User
Joined: Apr 2018
Posts: 15
Likes: 1
I have done the idle relearn 10-15 times at least. Each time the radio, ac, and headlights are turned off and the car is up to operating temp but the idle stays the same. I will try again later today though.
 
Reply
Old Apr 17, 2018 | 04:51 PM
  #4  
cleric670's Avatar
BANNED!!!
Joined: May 2017
Posts: 14,837
Likes: 2,497
From: Washington State
Coupe 6MT Premium RAS
Premier Member

And just to verify the reset DOES work yes? You see the light flashing the correct pattern and there doesn't appear to be anything about it that makes you think it DIDNT work correct?
 
Reply
Old Apr 17, 2018 | 04:56 PM
  #5  
yag's Avatar
yag
Thread Starter
|
Registered User
Joined: Apr 2018
Posts: 15
Likes: 1
Yessir check engine light flashes then turns solid then I'd start up the car and wait 20 seconds only to find it drops right back down to 200rpm. I've gone through those instructions a million times now I know it all by heart.
 
Reply
Old Apr 17, 2018 | 05:14 PM
  #6  
cleric670's Avatar
BANNED!!!
Joined: May 2017
Posts: 14,837
Likes: 2,497
From: Washington State
Coupe 6MT Premium RAS
Premier Member

What happens when you unplug the MAF while the engine is running?

I suspect you have a faulty ECU but you will need Nissan to diagnose that one.
 
Reply
Old Apr 20, 2018 | 05:48 AM
  #7  
Blue Dream's Avatar
I drove ttrank's car solo
iTrader: (50)
Joined: Mar 2009
Posts: 18,299
Likes: 1,488
From: By the sea, Tx
G35 sedan w/ too much money in mods
Premier Member

As cleric suggested you need to take it to a Nissan/Infiniti dealer to diagnose the issue. Definitely update the thread when you find out what the issue is to help others who might run into this problem.
 
Reply
Old Apr 20, 2018 | 12:19 PM
  #8  
yag's Avatar
yag
Thread Starter
|
Registered User
Joined: Apr 2018
Posts: 15
Likes: 1
When I unplugged the maf the car kept running but the idle would jump around 700-1000 rpm. I'll let y'all know if I solve this. My only issue with taking it to the dealership is I have a few breather mods. Cai 75mm tb and plenum spacer. They'll probably blame the idle on that. I know for a fact these arent causing the poor idle because when it was bone stock it idled the exact same if not worse. When I first brought the car to the dealership for an inspection they tried to scam me and they said nothing of the poor idle so I don't trust them. I plan on getting an uprev tune shouldn't that solve the issue sense you can input the idle levels manually?
 
Reply
Old Apr 20, 2018 | 01:24 PM
  #9  
cleric670's Avatar
BANNED!!!
Joined: May 2017
Posts: 14,837
Likes: 2,497
From: Washington State
Coupe 6MT Premium RAS
Premier Member

If it is an ECU problem then it will just lead to other problems later with the tune. Getting a diagnostic from Nissan will cost $150 or so but then you'll know where the problem lies. Their chain of events for troubleshooting starts with Consult-II recalibration and if it can't pass that or gives wrong values they would be able to immediately declare the ECU was the culprit.

EDIT: I just remembered something, you MUST be in park/neutral with an AT or with the gear shift in the neutral position for the 6MT. If you were in gear with the 6MT it can actually screw up the idle air recalibration for some dumb reason. Same with the AC controller, it needs to be turned OFF not just the AC compressor off.
 
Reply
Old Apr 21, 2018 | 09:57 PM
  #10  
yag's Avatar
yag
Thread Starter
|
Registered User
Joined: Apr 2018
Posts: 15
Likes: 1
Turns out I'm just a dumbass and was reading the tachomoter wrong. As far as the shaky idle is concerned I was told its not anything I should be concerned about. Thanks for the help
 
Reply
Old Apr 22, 2018 | 02:43 AM
  #11  
ScraggleRock's Avatar
Registered User
iTrader: (4)
Joined: Dec 2013
Posts: 6,811
Likes: 738
Yeah, gotta understand that the very first line on the taco-meter is 500rpm. The next 250 is actually 750.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Andy.
G35 Coupe V35 2003 - 07
3
Jul 13, 2017 05:46 PM
cfauvel
Engine, Drivetrain & Forced-Induction
13
Oct 31, 2016 09:14 AM
deathsupport
G35 Sedan V35 2003-06
15
Jul 5, 2015 09:36 AM
GErwin
G35 Sedan V36 2007- 08
9
Aug 31, 2011 12:07 PM
Skyliner
G35 Cars
2
Aug 14, 2006 08:39 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 11:13 PM.