Idle adjust 4.0 Impossible? - Jeep Cherokee Forum xjTalk
Jeep Cherokee Forum xjTalk
DetoursUSA.com
Advertise on xjtalk
  

Go Back   Jeep Cherokee Forum xjTalk > Jeep Comanche (MJ) > MJ - Technical Questions/Information

Notices

MJ - Technical Questions/Information Post your Jeep Comanche "MJ" technical questions and information here.

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 02-19-2011
88AMCOMANCHE's Avatar
88AMCOMANCHE 88AMCOMANCHE is offline
Level: Cherokee XJ
JD's Information
 
Join Date: Jan 2011
Location: SW FLA
Posts: 184
Thanks: 1
Thanked 14 Times in 11 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
Chats: 77
88AMCOMANCHE has a spectacular aura about88AMCOMANCHE has a spectacular aura about
windows_vistaie
Default Idle adjust 4.0 Impossible?

Got a friend who knows a lot about Jeeps as far as History & the different variations and seemed pretty sharp when it came to my 4.0 . My engine idles around 800 at startup but after it warms up about 3 minutes or so it will idle a steady 550 or so .....which is TOO LOW cuz mines a stick, & we know what happens when your driving & have to let off quikly & the engine "almost" wants to die,but doesnt quite die. But almost does.
So I mentioned one day about setting my idle up a bit to around 1000 so when it warms up it should be around 800. To which he says "ya cant adjust the idle on 4.0's theyre set how theyre set from the factory" .......I havent tried yet, but just find it a biot hard to believe. Just wondered what anyone elses opinions might be.
Reply With Quote
The Following User Says Thank You to 88AMCOMANCHE For This Useful Post:
cantab27 (02-20-2011)
  #2  
Old 02-20-2011
Outlaw's Avatar
Outlaw Outlaw is offline
Jack of All Trades
Josh's Information
 
Join Date: Jan 2011
Location: Charlotte, NC
Posts: 309
Thanks: 79
Thanked 32 Times in 28 Posts
Groans: 0
Groaned at 1 Time in 1 Post
Chats: 1020
Outlaw is a jewel in the roughOutlaw is a jewel in the roughOutlaw is a jewel in the roughOutlaw is a jewel in the rough
linuxubuntufirefox
Default Re: Idle adjust 4.0 Impossible?

Quote:
Originally Posted by 88AMCOMANCHE View Post
Got a friend who knows a lot about Jeeps as far as History & the different variations and seemed pretty sharp when it came to my 4.0 . My engine idles around 800 at startup but after it warms up about 3 minutes or so it will idle a steady 550 or so .....which is TOO LOW cuz mines a stick, & we know what happens when your driving & have to let off quikly & the engine "almost" wants to die,but doesnt quite die. But almost does.
So I mentioned one day about setting my idle up a bit to around 1000 so when it warms up it should be around 800. To which he says "ya cant adjust the idle on 4.0's theyre set how theyre set from the factory" .......I havent tried yet, but just find it a biot hard to believe. Just wondered what anyone elses opinions might be.
This is correct, the 4.0 has an IPS or Idle Position Sensor, it is not adjustable. I took mine out and it was Full of Carbon. A few hours later after drying idle was good. The sensor is right next to the TPS on the throttle body and is an easy clea/replace if needed.
__________________
Life is not about waiting for the storm to pass, it's about learning to MUD in the rain!
Reply With Quote
  #3  
Old 02-20-2011
Punisher's Avatar
 Punisher Punisher is offline
Site Subscriber!
Paul's Information
 
Join Date: Jul 2009
Location: Punta Gorda, Florida
Posts: 1,034
Thanks: 179
Thanked 115 Times in 82 Posts
Groans: 1
Groaned at 1 Time in 1 Post
Chats: 4939
Punisher is a splendid one to beholdPunisher is a splendid one to beholdPunisher is a splendid one to beholdPunisher is a splendid one to beholdPunisher is a splendid one to beholdPunisher is a splendid one to beholdPunisher is a splendid one to beholdPunisher is a splendid one to behold
windows_vistaie
Default Re: Idle adjust 4.0 Impossible?

Theres no way to adjust the idle on that... theres gotta be a vac leak of some kind or like Outlaw says ISP could be dirty...
__________________
You know that look women get when they want sex? Me neither!

Last edited by Punisher; 02-20-2011 at 12:13 PM.
Reply With Quote
  #4  
Old 02-20-2011
88AMCOMANCHE's Avatar
88AMCOMANCHE 88AMCOMANCHE is offline
Level: Cherokee XJ
JD's Information
 
Join Date: Jan 2011
Location: SW FLA
Posts: 184
Thanks: 1
Thanked 14 Times in 11 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
Chats: 77
88AMCOMANCHE has a spectacular aura about88AMCOMANCHE has a spectacular aura about
windows_vistaie
Default Re: Idle adjust 4.0 Impossible?

I will put that on my list of things to do ....the ISP* ....that wil be my starting point when I get to it~
Reply With Quote
  #5  
Old 02-24-2011
xj4life2's Avatar
xj4life2 xj4life2 is offline
Payless 4WD Chico Ca
Mark's Information
 
Join Date: Sep 2009
Location: On my mountian NOR CAL
Posts: 1,875
Thanks: 34
Thanked 799 Times in 546 Posts
Groans: 1
Groaned at 1 Time in 1 Post
Chats: 2951
xj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond reputexj4life2 has a reputation beyond repute
windows_xp_2003ie
View xj4life2's Twitter Profile
Default Re: Idle adjust 4.0 Impossible?

Well thats not completely true , there is an air bleed than can be manually adjuted but for all intents and purposes the IAC motor (idle air control) is normally the issue take it off clean the pintel on it and the passage in the TB both are carbon fouled. Put it back in and the jeep will rev to about 3k an then settle back down to the pre set idle speed. If you still have an Idle issue check the Throttle Pos sensor it may be bad or out of range. It can be adjusted check your manual for specs. If the issue persists I would replace the IAC motor. I had the same issue on mine and others and following these procedures they all got running right. Good Luck
__________________
Aint got no whistle, don't belch out smoke, but my V10 aint no joke !!!
Reply With Quote
  #6  
Old 02-24-2011
4.3LXJ's Avatar
4.3LXJ 4.3LXJ is offline
Super Moderator
Steve's Information
 
Join Date: Sep 2009
Location: Chico, CA
Posts: 20,881
Thanks: 3,982
Thanked 5,829 Times in 4,112 Posts
Groans: 0
Groaned at 6 Times in 6 Posts
Chats: 1649
4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute4.3LXJ has a reputation beyond repute
macossafari
Default Re: Idle adjust 4.0 Impossible?

Only one thing to add. The thing that determines the idle speed is the ECM, which controls the IAC. Theoretically it could be adjusted, but it would have to be reprogramed to do so and I don't know of anyone who can.
__________________
230 hp 4.3L Chevy
Built 4L60E with manual lockout
Atlas 4 speed
Griffin radiator
On board air
Warn 9.5ti on custom bumper
7.5" RE front and bastard pack rear on custom long arms
30 gal gas tank
lockers
And a bunch of other stuff
Reply With Quote
  #7  
Old 02-24-2011
steph74's Avatar
steph74 steph74 is offline
Ohhhh Nooooooooo
Stephane's Information
 
Join Date: Jul 2010
Location: Logan UT
Posts: 1,321
Thanks: 289
Thanked 249 Times in 192 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
Chats: 5527
steph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond reputesteph74 has a reputation beyond repute
windows_xp_2003firefox
View steph74's Twitter Profile
Default Re: Idle adjust 4.0 Impossible?

OK this is how I adjusted my idle... I am not saying it is an official way.
I too had problem of idling going down under 500rpm when warm, I also have a manual.

I bent the tab....see when the throttle cable attach on the TB, it is a tab that rest on some kind of pin. well I took a pair of pliers when engine was warm, and bent it in a little and after idle settled, kept adjusting it until I was happy.
Now it is idling fine at 750rpm....

I did that after I was sure that there was no exhaust leak (manifold bolt was not tight on the rear bolt) that there was no vacuum leak (usually high idle is the symptom for that) and after cleaning intake and adjusting TPS.

I know my IAC is acting up and some times it idles at 2 or 3000 rpm.... need to be changed but it is working for now...


So to sumarize... look into that little tab bending.....
(I can probably post pictures if my description is too vague )
__________________
"if yer not larnin sumptin new everday, check yer pulse."
Reply With Quote
Reply

Bookmarks

Tags
adjust, idle, impossible
Home Forums Articles Register FAQ Members List Calendar Search Today's Posts Mark Forums Read


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Idle speed? Switch_knuckles General Talk 8 02-09-2011 01:00 PM
Fast Idle for less than $20 4.3LXJ Modified 1 08-08-2010 06:23 AM
how do i adjust speedo after fitting 33s cantab27 Technical "HOW TO" Articles 10 05-14-2010 01:24 PM
Idle Stepper Motor & IAT BlueXJ 4.0 Liter Engine 0 11-07-2009 11:12 PM
How do you adjust hood height? Mudderoy OEM/Factory 6 05-02-2009 12:21 PM


Advertise with us through Google's Adsense Direct!

VigLink badge

Large Visitor Map

All times are GMT -5. The time now is 04:05 AM.

Powered by vBulletin® Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
Garage vBulletin Plugins by Drive Thru Online, Inc.

Style Provided By: Wrestling Clique - Wrestling Forums
Jeep, Cherokee, are copyrighted and trademarked to the Jeep/Chrysler Corporation
xjtalk is not in any way associated with Jeep or the Chrysler Corp.

no new posts
Ad Management plugin by RedTyger