Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WJ > Troubleshooting/Problems

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 02-17-2012, 01:00 PM
New Member
My Jeep: 1999 4.7L WJ
 
Join Date: Dec 2010
Location: Alberta, Canada
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
davealberta is on a distinguished road
Engine RPM flucuating at Idle

I have just purchased a 1999 WJ with a 4.7L engine.
When I start the engine from cold the rpm flucuates back and fourth between 2000 rpm and 1000 rpm. When I put in drive and drive the vehicle everything is fine.

It idles about 750 rpm when warm, but occasionally flucuates in idling for awhile.

Any suggestions on the possible cause would be appreciated.

I am uncertain as to whether sparks plugs or other items had been serviced prior to my buying the vehicle.
__________________

__________________
Reply With Quote
  #2  
Old 02-17-2012, 01:41 PM
Frango100's Avatar
The BEAST from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 4,329
Thanks: 8
Thanked 32 Times in 31 Posts
Rep Power: 524724
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: Engine RPM flucuating at Idle

Fluctuating rpm at idle is often caused by a dirty idle air passage and Idle Air Control motor plunjer in the throttle body. Clean this very well and try again.
Is it still fluctuating, then it is probably the TPS sensor.
Also when you dont know the history of the jeep, its good to change all oils/fluids/filters etc.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
Monroe Reflex shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
Reply

Thread Tools
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
4.7 HO Engine Rough Idle Problem rojpon74 Engine Performance/Intake/Exhaust 20 03-15-2012 08:28 PM
Loud Engine at 2000 RPM Old State Engine Performance/Intake/Exhaust 1 08-23-2011 02:59 PM
Overdrive & engine rpm question 402 Motoring Grand Cherokee - WK 4 03-09-2011 06:12 PM
Rough Idle, flashing engine light 05WKinPA Grand Cherokee - WK 7 01-24-2011 03:20 PM
Idle at what RPM? White05 Grand Cherokee - WK 4 06-17-2010 12:07 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 01:55 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community