Idle Problems - 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 > Idle Problems

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFS: Wranger BRIGHT License Plate LED! Just $3! Great valueRough Country Lift Kits and Parts!

Reply
Unread 09-27-2002, 09:30 PM   #1
JeepGuyRyan
Registered User
 
Join Date: Jun 2002
Location: Denver, Colorado
Posts: 106
Idle Problems

First off, where should the idle be on a 93 GC with the 4.0?

Second, what do you recomend for a rough idleing Engine? It only has 20,000 orig miles on it, recently had a tune up, (didn't seem to help much) It is very annoying to have the thing shaking so much at idle as if it is almost going to stall out.

__________________
-=Ryan=-
JeepGuyRyan is offline   Reply With Quote
Unread 09-28-2002, 09:43 PM   #2
Intrepidjeep
Registered User
 
Join Date: Mar 2002
Location: Cape Canaveral, Florida
Posts: 355
My father has a '93 -- I believe I recall him saying there's actually an idle screw on the throttle body. I believe he said it's covered by a little plug, which you can remove and replace after adjustment. I know for a fact there was one on the '87 4.0L engine I once had, but that would have been Renix throttle body, and yours is a different, larger bore throttle body. Still check to see if you can find the idle screw.

The throttle body may need to be cleaned out. Also the idle air control motor on the throttle body may need to be cleaned out. I believe it can simply be removed from the throttle body and sprayed out with carb cleaner. Of course, that IAC might actually be malfunctioning now.

Even with low miles, it's still 10 years old, so it could probably use a new cap & rotor if that wasn't done at the tuneup, along with new plugs and plug wires.
__________________
-- Marcus
Cape Canaveral, Florida
2005 Jeep Grand Cherokee Laredo 4.7L
2005 Dodge Durango SLT 4.7L
Intrepidjeep is offline   Reply With Quote
Unread 09-29-2002, 11:31 AM   #3
Intrepidjeep
Registered User
 
Join Date: Mar 2002
Location: Cape Canaveral, Florida
Posts: 355
Update: Talked with my father this morning -- he said the screw is there but it's JB-welded or otherwise locked in place, not adjustable. I know on the older 4.0L's it was adjustable, but I guess when they went to the Chrysler FI they took care of that.
__________________
-- Marcus
Cape Canaveral, Florida
2005 Jeep Grand Cherokee Laredo 4.7L
2005 Dodge Durango SLT 4.7L
Intrepidjeep is offline   Reply With Quote
Unread 09-29-2002, 02:32 PM   #4
Big Dumb White Guy
Registered User
 
Join Date: Dec 2001
Posts: 254
nope. it's some kind of loc-tite stuff. take the TB off and clean it and try to adjust it. i tried and it has made no difference. still idles like crap!
__________________
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
Unread 09-29-2002, 04:10 PM   #5
Intrepidjeep
Registered User
 
Join Date: Mar 2002
Location: Cape Canaveral, Florida
Posts: 355
You can use a voltmeter to test the AIC -- it's supposed to return a specific voltage range when closed versus open, I believe. Have to check the manual. My father's '93 GC did have a bad AIC at one time that he diagnosed that way -- the voltages were way off.
__________________
-- Marcus
Cape Canaveral, Florida
2005 Jeep Grand Cherokee Laredo 4.7L
2005 Dodge Durango SLT 4.7L
Intrepidjeep is offline   Reply With Quote
Unread 09-30-2002, 06:15 AM   #6
ALS59LTD
Registered User
2003 TJ Wrangler 
 
Join Date: Aug 2002
Location: NY
Posts: 75
the idle is controlled by the computer with the IAC (Idle Air Control) valve. you should check/replace the valve. they can get pretty expensive. I remember the one for my camaro was like $70.

Where did you find a 93 with 20,000 miles??????
__________________
-Alex
http://www.jeepforum.com/forum/f22/turbocharged-2-4l-jeep-tj-me-too-2255329/
ALS59LTD is offline   Reply With Quote
Unread 09-30-2002, 06:22 AM   #7
Big Dumb White Guy
Registered User
 
Join Date: Dec 2001
Posts: 254
Autozone was like under $60.
__________________
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
Unread 09-30-2002, 03:56 PM   #8
Intrepidjeep
Registered User
 
Join Date: Mar 2002
Location: Cape Canaveral, Florida
Posts: 355
Yeah, a '93 with 20,000 actual miles would be a pretty sweet deal if it's in good shape.
__________________
-- Marcus
Cape Canaveral, Florida
2005 Jeep Grand Cherokee Laredo 4.7L
2005 Dodge Durango SLT 4.7L
Intrepidjeep is offline   Reply With Quote
Unread 10-03-2002, 07:42 PM   #9
rebrock57
Registered User
 
Join Date: May 2002
Location: FL
Posts: 3
My 94 4.0 had a rough idle, it turned out that the stock motor mounts had weakened, allowing the engine vibrations to be transmitted through to the frame and body, Replaced the motor mounts and it idles as smoothly as new, now with 156k miles.
rebrock57 is offline   Reply With Quote
Reply
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.