4.0 ZJ intermittent stumble in idle - 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 > 4.0 ZJ intermittent stumble in idle

Premium LED Lighting by VISION X, Proudly sold at ROCKRIDGFS: Wrangler RGB Multicolor Fog Light LEDs: Awesome EffectCess Recovery Gear Snatch Tow Strap OffRoad @ ROCKRIDGE4WD

Reply
Unread 08-23-2013, 11:12 PM   #1
JaneLee
Registered User
1994 ZJ 
 
Join Date: Aug 2013
Location: Richmond, IN
Posts: 35
4.0 ZJ intermittent stumble in idle

funky issue and no solutions in sight. i have a 94 4.0 I6. it has an intermittent slight stumble in P or N but RPM is normal. As soon as you put it in any gear the RPM drops to about 5-600, stumbles and acts like it wants to die. Cleaned the throttle body and butterfly, replaced the TPS, MAP sensor and IAC. No vacuum leaks, all injectors working with no leaks there, fuel pressure is normal at 33psi. No change in running with or without O2 screwed in so i don't think it's the CAT and CAT has no rattle at all. It wont make to a shop so i can get it scanned. Any suggestions?

JaneLee is offline   Reply With Quote
Unread 08-24-2013, 06:17 AM   #2
newfieZJ
Registered User
1995 ZJ 
 
Join Date: May 2008
Location: , Alberta
Posts: 6,406
Start by cleaning your grounds .

Re-seat all your fuses and relays everywhere , and your PCM connection . Clean as needed .

Clean battery terminals

Consider pulling the crank sensor and cleaning it . It's a magnetic pick up and it picks up small metallic debris . Could be a weak signal .

If your check engine light(CEL) is on , use the key method to retrieve codes . Key to on(not start) off , on , off , on . Then the codes will blink via the CEL by blinking . Blink blink blink space blink blink = code 32

Try this first , it's free . If no luck , post results .
newfieZJ is offline   Reply With Quote
Unread 08-24-2013, 09:28 AM   #3
JaneLee
Registered User
1994 ZJ 
 
Join Date: Aug 2013
Location: Richmond, IN
Posts: 35
throws no codes, just start and stop 12-55. battery term clean. pcm?
JaneLee is offline   Reply With Quote
Unread 08-24-2013, 01:20 PM   #4
Oldfrog
Web Wheeler
1997 ZJ 
 
Join Date: Feb 2008
Location: Louisiana/Texas
Posts: 3,785
Merely unscrewing the o2 sensor will not give you the desired results for a test. Disconnect it from the connector.
__________________
Cajun Recipes and Fishing tips

Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
Oldfrog is offline   Reply With Quote
Unread 08-24-2013, 02:07 PM   #5
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,346
Quote:
Originally Posted by Oldfrog View Post
Merely unscrewing the o2 sensor will not give you the desired results for a test. Disconnect it from the connector.
good catch oldfrog. aren't we fixing the same jeep in another thread?
ZeeJay1997 is online now   Reply With Quote
Unread 08-24-2013, 02:22 PM   #6
JaneLee
Registered User
1994 ZJ 
 
Join Date: Aug 2013
Location: Richmond, IN
Posts: 35
probably lol had internet/puter issues. mine went down and had to borrow being i'm stranded in another state
JaneLee is offline   Reply With Quote
Unread 08-24-2013, 02:25 PM   #7
ZeeJay1997
Registered User
1997 ZJ 
 
Join Date: Dec 2008
Location: Sweet Home, Alabama
Posts: 6,346
disconnect o2 sensor. the connector should be under the manifolds
ZeeJay1997 is online now   Reply With Quote




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.