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

Poor idle after changing valve cover gaskets.

Old 04-03-2012, 01:58 PM
  #1  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
Poor idle after changing valve cover gaskets.

As title says, i changed both valve cover gaskets and its idling horribly....when cold it idles ok around 1200-1000 but feels like it misses or stutters....when warmed up its way worse, hunting between 750 and 300 rpms, shakking badly etc...i double checked everything for intake leaks etc...even sprayed some either around UIM gasket to check for leaks....im wondering if its IACV finally crapped on me.

I should add that when driven the car drives beautifully and leaks not a drop of oil anymore...., however when i clutch it to come to a stop it idles almost to 0 before catching itself and even dies sometimes if i dont tap the gas....

plz help, thank you!!

EDIT* new UIM-LIM gasket installed when it was off too...
Boothers96 is offline  
Old 04-03-2012, 02:03 PM
  #2  
Got Retrofit?
iTrader: (34)
 
ChrisMan287's Avatar
 
Join Date: Jul 2008
Location: NY
Posts: 14,802
Vacuum leak.
ChrisMan287 is offline  
Old 04-03-2012, 02:29 PM
  #3  
Senior Member
iTrader: (3)
 
aackshun's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 5,404
Raise idle, spray wd-40 all over the UIM gaskets, if it dies when you spray it, you sir have located your vacuum leak.
aackshun is offline  
Old 04-03-2012, 03:05 PM
  #4  
Senior Member
 
vilmaxima's Avatar
 
Join Date: Nov 2005
Location: London, ON, CANADA
Posts: 585
Originally Posted by aackshun
Raise idle, spray wd-40 all over the UIM gaskets, if it dies when you spray it, you sir have located your vacuum leak.
He did not raise idle, but did spray wd-40 over the UIM gasket(in his post)
Im guessing IACV if it is only the idle that is ****ty, but when you give it gas is ok. All your vacuum hoses connected good? Take your IACV off clean it, and test that all connectors on IACV are functioning. Changed both of my valve cover gaskets, spark pluk gaskets(one was leaking oil) a couple years ago, but did not have issues like you so

Last edited by vilmaxima; 04-03-2012 at 03:10 PM.
vilmaxima is offline  
Old 04-03-2012, 03:49 PM
  #5  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
Originally Posted by vilmaxima
He did not raise idle, but did spray wd-40 over the UIM gasket(in his post)
Im guessing IACV if it is only the idle that is ****ty, but when you give it gas is ok. All your vacuum hoses connected good? Take your IACV off clean it, and test that all connectors on IACV are functioning. Changed both of my valve cover gaskets, spark pluk gaskets(one was leaking oil) a couple years ago, but did not have issues like you so
Thats what i was thinkin.....ill recheck all hoses tonight i did replace a few hoses (breateher hose between both vc, coolant hose on rear of uim n a few brittle vac hoses right under the tb) i also cleaned maf, tb, egr tube and iacv as per the thread on that subject and replaced all gaskets w oem nissan.
Boothers96 is offline  
Old 04-03-2012, 03:50 PM
  #6  
Senior Member
iTrader: (3)
 
ShocknAwe's Avatar
 
Join Date: Dec 2011
Location: Atlanta, Ga
Posts: 3,292
hope its your IACV and not a harness issue. Moving an old harness around to remove the UIM can break wire on the quickness.
ShocknAwe is offline  
Old 04-03-2012, 04:03 PM
  #7  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
Originally Posted by ShocknAwe
hope its your IACV and not a harness issue. Moving an old harness around to remove the UIM can break wire on the quickness.
My VERY first thought and worry.....but i would think if it was a harness issue it wouldnt only b on idle....it would affect the car w load on and off the engine and at all rpms.....also btw no codes
Boothers96 is offline  
Old 04-03-2012, 04:12 PM
  #8  
Senior Member
iTrader: (3)
 
ShocknAwe's Avatar
 
Join Date: Dec 2011
Location: Atlanta, Ga
Posts: 3,292
Not if its the IACV because it only takes over at idle, part of the ECU that controls the IACV can fry as well.When I had a screwy idle I first checked for leaks and such and found none. THen I got an IACV code and was relieved becuase I thought I would go to the pull-a-part, swap it out and be done. Didnt fix it. Come to find out the ECU can fry and you need to repair or for most people, replace it. Test the IACV. Should be 30ohms resistance. Then trace the wiring. First check for leaks though, hoses can have a crack
ShocknAwe is offline  
Old 04-03-2012, 04:13 PM
  #9  
Senior Member
 
vilmaxima's Avatar
 
Join Date: Nov 2005
Location: London, ON, CANADA
Posts: 585
Originally Posted by Boothers96
My VERY first thought and worry.....but i would think if it was a harness issue it wouldnt only b on idle....it would affect the car w load on and off the engine and at all rpms.....also btw no codes
Exactly as u stated, unless the wires only affect idle. Maybe a wire that is hitting ground sometime(small split), give it a good visual check. Everywhere. Also when did you clean or replace your air filter, fuel filter, or spark plugs? What I forgot, how is your main ground wire? Or do u have a grounding kit?

Last edited by vilmaxima; 04-03-2012 at 04:18 PM.
vilmaxima is offline  
Old 04-03-2012, 04:46 PM
  #10  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
Originally Posted by vilmaxima
Exactly as u stated, unless the wires only affect idle. Maybe a wire that is hitting ground sometime(small split), give it a good visual check. Everywhere. Also when did you clean or replace your air filter, fuel filter, or spark plugs? What I forgot, how is your main ground wire? Or do u have a grounding kit?
Replaced fuel filter w z32 about 2000mi ago, spark plugs r ngk platinums replaced same time, and air filter is k&n cone snd was cleaned/oiled last fall......coils are all used off low mileage junk car been on their less than a month....i ohm tested rear injectors since i had uim off....all tested 12.1-12.6
Boothers96 is offline  
Old 04-03-2012, 04:49 PM
  #11  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
Oh and i have a ground kit.....one from bat-body, one uim-firewall, one tb-body, one timing cover-body. All are 2 ga w gold terminals
Boothers96 is offline  
Old 04-03-2012, 05:08 PM
  #12  
Member who somehow became The President of The SE-L Club
iTrader: (19)
 
njmaxseltd's Avatar
 
Join Date: Jun 2001
Posts: 16,033
Originally Posted by ShocknAwe
, part of the ECU that controls the IACV can fry as well.u
This issue only applies to 5th gens.
njmaxseltd is offline  
Old 04-03-2012, 05:36 PM
  #13  
Senior Member
iTrader: (3)
 
ShocknAwe's Avatar
 
Join Date: Dec 2011
Location: Atlanta, Ga
Posts: 3,292
Originally Posted by njmaxseltd
This issue only applies to 5th gens.
your 100% sure of that? Because if so then I need to reevaluate my solution. I havent checked my harness though, that and the ECU are all I have left
ShocknAwe is offline  
Old 04-03-2012, 05:59 PM
  #14  
Got Retrofit?
iTrader: (34)
 
ChrisMan287's Avatar
 
Join Date: Jul 2008
Location: NY
Posts: 14,802
Originally Posted by ShocknAwe
your 100% sure of that? Because if so then I need to reevaluate my solution. I havent checked my harness though, that and the ECU are all I have left
He's 100% right.
ChrisMan287 is offline  
Old 04-04-2012, 04:40 AM
  #15  
Member who somehow became The President of The SE-L Club
iTrader: (19)
 
njmaxseltd's Avatar
 
Join Date: Jun 2001
Posts: 16,033
IACV will not cause a rough idle (misfire). It only controls idle speed.
If the valve fails to function and is closed the idle speed will default to the throttle body setting, which should be about 550. If it fails open you'll have a very high idle.
The valve only controls air flow which in turn sets idle speed.
njmaxseltd is offline  
Old 04-04-2012, 04:58 AM
  #16  
Senior Member
 
cashoit's Avatar
 
Join Date: Sep 2009
Location: Worcester, MA
Posts: 4,011
a simple resistance test for the IACV will tell u if its good or not. Test IACV per how tos
cashoit is offline  
Old 04-04-2012, 12:45 PM
  #17  
Senior Member
 
DBear's Avatar
 
Join Date: Apr 2006
Location: Oakland, CA
Posts: 704
Make sure your coilpack connectors are snapped all the way on. It's a long shot, since that would likely affect driveability too, but it's easy enough to check.
DBear is offline  
Old 04-04-2012, 02:15 PM
  #18  
Supporting Maxima.org Member
iTrader: (9)
 
NABU6's Avatar
 
Join Date: Feb 2003
Location: Bronx, New York
Posts: 385
Check your throttle cable to make sure its not to loose.
NABU6 is offline  
Old 04-04-2012, 02:16 PM
  #19  
Member
 
Timm80's Avatar
 
Join Date: Sep 2011
Location: St. Charles, IL
Posts: 119
Check all your hoses, they get brittle and crack really easily. I replaced my valve cover gaskets a few months ago and had to get 3 new hoses because they broke or cracked badly. There are a lot of little hoses connected to the UIM and throttle body. When you took both off did you number each hose and connecter and what it attaches too? Thats what I did and putting everything back together was a breeze. If you didn't, visit one of your friends who has a same year maxima as yours and compare everything in your car to his to make sure you put everything back together properly. My guess is you forgot to plug a hose back in or plugged one of the hoses into the wrong spot, seeing as how this started after you put everything back together.
Timm80 is offline  
Old 04-04-2012, 03:46 PM
  #20  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
Originally Posted by Timm80
Check all your hoses, they get brittle and crack really easily. I replaced my valve cover gaskets a few months ago and had to get 3 new hoses because they broke or cracked badly. There are a lot of little hoses connected to the UIM and throttle body. When you took both off did you number each hose and connecter and what it attaches too? Thats what I did and putting everything back together was a breeze. If you didn't, visit one of your friends who has a same year maxima as yours and compare everything in your car to his to make sure you put everything back together properly. My guess is you forgot to plug a hose back in or plugged one of the hoses into the wrong spot, seeing as how this started after you put everything back together.
I didnt label....smh...and i also dont have friends around w maximas.....i thought of "test driving" the only one on cl in tyler n check it out.....i could also go to a pick n pull n check out vac routing.....or if someone w a 95 would b awesome n post a pic just under the tb where all the little hoses connect id b much obliged.....ps its not coils, iacv, or maf, and i dont find any vac leaks.....REALLY hoping its not electrical at this point!!
Boothers96 is offline  
Old 04-04-2012, 06:13 PM
  #21  
Junior Member
 
BrooklynCyclone's Avatar
 
Join Date: May 2009
Location: brooklyn
Posts: 67
Definitely a vac,loose or in a wrong location since when driven all is well.....
BrooklynCyclone is offline  
Old 04-04-2012, 08:04 PM
  #22  
Member
 
iDuty's Avatar
 
Join Date: Nov 2006
Posts: 164
Originally Posted by ChrisMan287
Vacuum leak.
What he wrote.

There is ample potential for creating a vacuum leak doing this job.

Recheck all the vacuum hoses and breather hoses.
iDuty is offline  
Old 04-06-2012, 04:47 PM
  #23  
Member
Thread Starter
iTrader: (11)
 
Boothers96's Avatar
 
Join Date: Oct 2006
Location: Sioux City, Ia
Posts: 241
ok so i went over this again today checking and replacing more hoses as i went....and i found the issue. It was the egr valve gasket, for some reason it had slipped off the far bolt and was hanging by the front bolt (bolt you can see)....so i got it on there right, put it all back together and what do you kno.....car runs like it should.

I appreciate all the help you all give we with this car...i am limited on knowledge but willing to try and learn whatever! thanks again!!
Boothers96 is offline  
Old 04-07-2012, 12:12 AM
  #24  
Senior Member
iTrader: (2)
 
flynlr's Avatar
 
Join Date: Oct 2002
Posts: 364
glad you found the problem . I was going to post basically that. when I did my valve covers years ago . I left the EGR tube bolts loose and had exactly that problem . tightened them up and idled perfect after that
flynlr is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
mvm062
Infiniti I30/I35
3
11-30-2020 09:00 AM
captchaos
4th Generation Maxima (1995-1999)
17
03-15-2016 12:18 PM
minsbang
8th Generation Maxima (2016-)
1
09-11-2015 08:48 PM
dcam0326
5th Generation Maxima (2000-2003)
8
09-07-2015 07:26 AM
03VQMAX
General Maxima Accessories (All Generations)
1
09-05-2015 03:47 PM


Thread Tools
Search this Thread
Quick Reply: Poor idle after changing valve cover gaskets.



All times are GMT -7. The time now is 03:04 AM.