Adjust Idle Speed - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > Adjust Idle Speed

Thanksgiving/Black Friday/Cyber Monday Deals at JeepinOutfIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed LineBlack Friday- Cyber Monday Deals at jeepHut

Reply
Unread 03-04-2004, 12:58 PM   #1
dwills898
Registered User
 
Join Date: Oct 2003
Posts: 87
Adjust Idle Speed

Does anyone know how to adjust the idle speed on a 93 grand cherokee, I cleaned my Idle Air Control and now it idles better, but still to low. I want to increase the idle speed. It idles around 500 rpm.

dwills898 is offline   Reply With Quote Quick reply to this message
Unread 03-04-2004, 01:01 PM   #2
ZickZJ
Registered User
1990 YJ Wrangler 
 
Join Date: Oct 2003
Location: Beloit, WI
Posts: 246
Quote:
Originally Posted by dwills898
Does anyone know how to adjust the idle speed on a 93 grand cherokee, I cleaned my Idle Air Control and now it idles better, but still to low. I want to increase the idle speed. It idles around 500 rpm.

You can't adjust it, its electronically controlled by the IAC. Around 500 rpms is about normal for Grand Cherokees for some reason.
__________________
Sold 90' YJ, 4.2, Weber, 4" Procrap, 33" BFG MTs, 8.8 w/ 4.10s & LSD, SYE & Tomwoods DS, Dual Optimas, Jacobs, Electric fan.

97' ZJ, SOLD
ZickZJ is offline   Reply With Quote Quick reply to this message
Unread 03-04-2004, 01:29 PM   #3
dwills898
Registered User
 
Join Date: Oct 2003
Posts: 87
Quote:
Originally Posted by ZickZJ
You can't adjust it, its electronically controlled by the IAC. Around 500 rpms is about normal for Grand Cherokees for some reason.
Yes but the iac is controlled by the main computer, and the IAC can only adjust to a certain point.
dwills898 is offline   Reply With Quote Quick reply to this message
Unread 03-04-2004, 01:38 PM   #4
3D-Dave
Registered User
 
Join Date: Feb 2004
Location: Austin, TX
Posts: 19
Mine idles at 750 on the mark. No fluxuating.
3D-Dave is offline   Reply With Quote Quick reply to this message
Unread 03-05-2004, 08:44 AM   #5
Big Dumb White Guy
Registered User
 
Join Date: Dec 2001
Posts: 254
so does anyone know of somewhere that can reprogram the 'puter?
__________________
repost Nazi's suck!

A guy walks into the psychiatrist office wearing only Glad Wrap shorts. The shrink says, "Well, I can clearly see you're nuts."
Big Dumb White Guy is offline   Reply With Quote Quick reply to this message
Unread 03-05-2004, 03:27 PM   #6
Saleen4971
Registered User
 
Join Date: Jan 2004
Location: Setauket, LI
Posts: 236
why do you need to adjust it?
__________________
1998 5.9 Limited
ET: 14.3@94MPH

Engine/Trans
- Full Kolak Exhaust (ML's FM70) - FIPK2 - APS 52mm TB - MSD Blaster SS - A3923's - Magnecor's - MP ECU - 180 robertshaw t-stat - Relocated IAT - E.H. M1 - B&M Trans Cooler

Susupension/Brakes
- Addco 1.25" Military front & 7/8" rear sways - Edelbrock IAS shocks - OME S.S - Stilens Front & Rear

Coming Soon :
Level10 Stage 3 46RE - WJ knuckle conversion
Saleen4971 is offline   Reply With Quote Quick reply to this message
Unread 03-05-2004, 08:25 PM   #7
Choff
Registered User
 
Join Date: Nov 2003
Location: Fargo, ND
Posts: 17
Could be worse... I replaced the O2 sensor on mine and now it idles at 1700!
No idea how to fix that...
'93 4.0L
Choff is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 02:12 AM   #8
dwills898
Registered User
 
Join Date: Oct 2003
Posts: 87
Quote:
Originally Posted by Saleen4971
why do you need to adjust it?
It is to low and causes vibration.
dwills898 is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 10:07 AM   #9
MikeRuth
Registered User
 
Join Date: Jul 2002
Location: Southern California
Posts: 28
Quote:
Originally Posted by dwills898
It is to low and causes vibration.
I don't know if this helps but on my 94 GC there is a mechanical stop on the manifold. Now it is in such a position that a normal tool(screwdriver, etc)can not be used, I'm guess there is a special service tool that can be used or some creativity.
No doubt if you raise that screw the idle will be higher.
MikeRuth is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 10:10 AM   #10
MikeRuth
Registered User
 
Join Date: Jul 2002
Location: Southern California
Posts: 28
Quote:
Originally Posted by Choff
Could be worse... I replaced the O2 sensor on mine and now it idles at 1700!
No idea how to fix that...
'93 4.0L
After replacing the O2 sensor and having a high idle I would guess the output of that sensor is incorrect for the computer.

Disconnect the battery for 1 hour and reconnect it. that will reset the computer. After doing that on my 94 Cherokee I had to drive it around the block a couple times to get the idle to come back to normal, as it was a bit low.
MikeRuth is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 10:21 AM   #11
Swamp Boy
Registered User
1993 ZJ 
 
Join Date: Jan 2003
Location: New Orleans
Posts: 1,327
It can be done manually ...There is a small cap on the passenger side of the throttle body when looking from the front..
Pop out the metal cap and there is a torx screw under that .... It will open up the butterfly which in turn raises your Idle..

I have a pic in my stupid imagestation account but I cant post it..



Here you go .. I transfered it to my personal website..

Good luck..

Carl
__________________
Just another soccer moms Grocery getter....
[Url]http://www.jeepforum.com/gallery/files//8/5/6/5/hatt034.jpg[/url]
Swamp Boy is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 01:11 PM   #12
dwills898
Registered User
 
Join Date: Oct 2003
Posts: 87
Quote:
Originally Posted by Swamp Boy
It can be done manually ...There is a small cap on the passenger side of the throttle body when looking from the front..
Pop out the metal cap and there is a torx screw under that .... It will open up the butterfly which in turn raises your Idle..

I have a pic in my stupid imagestation account but I cant post it..



Here you go .. I transfered it to my personal website..

Good luck..

Carl

Wich one in the picture is it?
dwills898 is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 07:11 PM   #13
Meerkat
Registered User
1996 ZJ 
 
Join Date: Apr 2003
Location: Belle, WV
Posts: 4,930
Quote:
Originally Posted by dwills898
Wich one in the picture is it?

If the plug is intact, I really must caution against adjusting this screw...
tb.jpg  
__________________
Warren
Black 1996 5.2L ZJ Limited
Meerkat is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 08:48 PM   #14
dwills898
Registered User
 
Join Date: Oct 2003
Posts: 87
Quote:
Originally Posted by wvd
If the plug is intact, I really must caution against adjusting this screw...
This is looking from the front of the vehicle right, and why do you caution against it?
dwills898 is offline   Reply With Quote Quick reply to this message
Unread 03-06-2004, 09:38 PM   #15
Meerkat
Registered User
1996 ZJ 
 
Join Date: Apr 2003
Location: Belle, WV
Posts: 4,930
Quote:
Originally Posted by dwills898
This is looking from the front of the vehicle right, and why do you caution against it?

Yes, it's from the front of the vehicle.
If the plug is intact, then it's likely nobody has messed with the screw behind it. The engine's idle speed is determined by several inputs: air conditioning, power steering, cold and warm running, etc. If one or more of the inputs used to set the idle speed is wrong, then compensating for it by adjusting that screw is only masking the real problem. Are you positive the AIC is operating properly? There is a test procedure in the Haynes manual to check the AIC. It also says that if the AIC tests good, then the PCM is suspect.
__________________
Warren
Black 1996 5.2L ZJ Limited
Meerkat is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
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


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.