Rough Idle help - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 02-20-2012, 10:22 AM   #1
Jeeper
 
bal31's Avatar
 
Join Date: Aug 2010
Location: Tennessee
Posts: 80
Rough Idle help

I have a 2002 TJ with a 4.0....IT has a little bit of a rough idle. Nothing bad, but just slightly rough. IT has 70,000 miles on it. I took the Throttle body off and cleaned it the TPS and the IAC. I also changed the plugs and put seafoam in the gas. I still have a rough idle. Any other ideas of things i can do??

bal31 is offline   Quote Quick Reply
Old 02-20-2012, 11:30 AM   #2
Jeeper
 
mudmagnet63's Avatar
 
Join Date: Feb 2012
Location: Whiskey River OK
Posts: 555
Plug wires? an easy way to check raise the hood at nite and look for sparking. Much better than gettin bit. or bad gas

mudmagnet63 is offline   Quote Quick Reply
Old 02-20-2012, 11:33 AM   #3
Commercial Member

WF Supporting Member
 
kfdjason7620's Avatar
 
Join Date: Apr 2011
Location: Kenly, NC
Posts: 3,962
2000 and newer have no plug wires
kfdjason7620 is offline   Quote Quick Reply
Old 02-20-2012, 11:59 AM   #4
Jeeper
 
mudmagnet63's Avatar
 
Join Date: Feb 2012
Location: Whiskey River OK
Posts: 555
Quote:
Originally Posted by kfdjason7620 View Post
2000 and newer have no plug wires
Learn something new everyday. Coil Packs I guess?
mudmagnet63 is offline   Quote Quick Reply
Old 02-20-2012, 12:16 PM   #5
Commercial Member

WF Supporting Member
 
kfdjason7620's Avatar
 
Join Date: Apr 2011
Location: Kenly, NC
Posts: 3,962
That's right, well actually they switched over at mid year 1999
kfdjason7620 is offline   Quote Quick Reply
Old 02-20-2012, 12:29 PM   #6
Jeeper
 
bal31's Avatar
 
Join Date: Aug 2010
Location: Tennessee
Posts: 80
I was thinking possibly and O2 sensor???
bal31 is offline   Quote Quick Reply
Old 02-20-2012, 12:47 PM   #7
Commercial Member

WF Supporting Member
 
kfdjason7620's Avatar
 
Join Date: Apr 2011
Location: Kenly, NC
Posts: 3,962
Had bad gas mileage?
kfdjason7620 is offline   Quote Quick Reply
Old 02-20-2012, 02:04 PM   #8
Jeeper
 
bal31's Avatar
 
Join Date: Aug 2010
Location: Tennessee
Posts: 80
Nope...getting between 18-20 mpg... I have had a few emissions codes( P0442, P0455, P0456). Checked all of the EVAP lines and fuel lines. Can't find any leaks. Replaced gas cap. it is odd to me that my gas mileage is still really good.
bal31 is offline   Quote Quick Reply
Old 02-21-2012, 06:57 AM   #9
Jeeper
 
bal31's Avatar
 
Join Date: Aug 2010
Location: Tennessee
Posts: 80
Bump...
bal31 is offline   Quote Quick Reply
Old 02-21-2012, 07:02 AM   #10
Jeeper
 
wwch99tj's Avatar
 
Join Date: Mar 2011
Location: Felton Delaware
Posts: 4,708
You said you were thinking 02 sensor try unplugging it and see if it runs any better, when you unplug it it will run off of the computer presets. Does it idle rough all the time when its cold and warmed up
wwch99tj is offline   Quote Quick Reply
Old 02-21-2012, 07:27 AM   #11
Jeeper
 
AVtj03's Avatar
 
Join Date: Jul 2011
Location: Villa Park, Il
Posts: 160
Quote:
Originally Posted by wwch99tj View Post
You said you were thinking 02 sensor try unplugging it and see if it runs any better, when you unplug it it will run off of the computer presets. Does it idle rough all the time when its cold and warmed up
won't it run worse if you do that?

o2 sensor is part of regular maintenance that commonly gets overlooked (me too). I think they should be changed out ever 75k to 100k. I have 117k on mine, and its hasn't been changed.

I had a pretty rough idle and it ended up being my #5 plug. After I changed my plugs, it obviously ran a lot better.

It really depends on you and how rough your idle is. It wouldn't hurt to check your coil packs and possibly change out the o2 sensor. Good Luck!
AVtj03 is offline   Quote Quick Reply
Old 02-21-2012, 07:31 AM   #12
Jeeper
 
wwch99tj's Avatar
 
Join Date: Mar 2011
Location: Felton Delaware
Posts: 4,708
Quote:
Originally Posted by AVtj03

won't it run worse if you do that?
No it won't run worse if you unplug it. It runs worse with it plugged in feeding the computer the wrong information.
wwch99tj is offline   Quote Quick Reply
Old 02-22-2012, 07:12 AM   #13
Jeeper
 
AVtj03's Avatar
 
Join Date: Jul 2011
Location: Villa Park, Il
Posts: 160
Quote:
Originally Posted by wwch99tj View Post
No it won't run worse if you unplug it. It runs worse with it plugged in feeding the computer the wrong information.
ya, guess ur right.

AVtj03 is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
2.5L or 4.0L please help Jatt-YJ YJ Tech Forum 145 03-07-2012 11:13 PM
Electronics have gone haywire!!! Help needed Chris M JK General Discussion Forum 3 02-20-2012 09:36 AM
Please help tires got cut !!!! Rusty_Shakleford TJ General Discussion Forum 13 02-20-2012 09:34 AM
Idle Problems c_goodnow TJ General Discussion Forum 5 02-20-2012 12:13 AM
Idle up control switch rbraden1970 Builders Corner 2 02-19-2012 10:37 PM


logo carid shop wrangler parts carid fender flares custom wheels store avs deflectors at carid

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 02:55 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC