Low idle when AC is turned off - G35Driver - Infiniti G35 & G37 Forum Discussion

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

Low idle when AC is turned off

Reply

 
 
 
  #1  
Old 04-17-2018, 04:32 PM
yag
yag is offline
Registered User
Thread Starter
Join Date: Apr 2018
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
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 With Quote
  #2  
Old 04-17-2018, 05:34 PM
cleric670@gmail's Avatar
BANNED!!!
Join Date: May 2017
Location: Washington State
Posts: 4,812
Thanked 489 Times in 465 Posts
Coupe 6MT Premium RAS
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 With Quote
  #3  
Old 04-17-2018, 05:48 PM
yag
yag is offline
Registered User
Thread Starter
Join Date: Apr 2018
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
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 With Quote
  #4  
Old 04-17-2018, 05:51 PM
cleric670@gmail's Avatar
BANNED!!!
Join Date: May 2017
Location: Washington State
Posts: 4,812
Thanked 489 Times in 465 Posts
Coupe 6MT Premium RAS
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 With Quote
  #5  
Old 04-17-2018, 05:56 PM
yag
yag is offline
Registered User
Thread Starter
Join Date: Apr 2018
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
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 With Quote
  #6  
Old 04-17-2018, 06:14 PM
cleric670@gmail's Avatar
BANNED!!!
Join Date: May 2017
Location: Washington State
Posts: 4,812
Thanked 489 Times in 465 Posts
Coupe 6MT Premium RAS
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 With Quote
  #7  
Old 04-20-2018, 06:48 AM
Blue Dream's Avatar
I drove ttrank's car solo
iTrader: (50)
Join Date: Mar 2009
Location: By the sea, Tx
Posts: 17,601
Thanked 1,342 Times in 1,098 Posts
G35 sedan w/ too much money in mods
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 With Quote
  #8  
Old 04-20-2018, 01:19 PM
yag
yag is offline
Registered User
Thread Starter
Join Date: Apr 2018
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
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 With Quote
  #9  
Old 04-20-2018, 02:24 PM
cleric670@gmail's Avatar
BANNED!!!
Join Date: May 2017
Location: Washington State
Posts: 4,812
Thanked 489 Times in 465 Posts
Coupe 6MT Premium RAS
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 With Quote
  #10  
Old 04-21-2018, 10:57 PM
yag
yag is offline
Registered User
Thread Starter
Join Date: Apr 2018
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
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 With Quote
  #11  
Old 04-22-2018, 03:43 AM
ScraggleRock's Avatar
Registered User
iTrader: (4)
Join Date: Dec 2013
Posts: 6,790
Thanks: 0
Thanked 711 Times in 604 Posts
Yeah, gotta understand that the very first line on the taco-meter is 500rpm. The next 250 is actually 750.
 
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Andy.
G35 Coupe V35 2003 - 07
3
07-13-2017 06:46 PM
cfauvel
Engine, Drivetrain & Forced-Induction
13
10-31-2016 10:14 AM
deathsupport
G35 Sedan V35 2003-06
15
07-05-2015 10:36 AM
GErwin
G35 Sedan V36 2007- 08
9
08-31-2011 01:07 PM
Skyliner
G35 Cars
2
08-14-2006 09:39 PM


Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Low idle when AC is turned off


Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: