Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Strange idle

Thread Tools
 
Search this Thread
 
Old Oct 29, 2013 | 08:53 PM
  #1  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default Strange idle

So my Jeep (2001 XJ 4x4 automatic) has been running weird lately. Basically it started to idle really rough as if it was going to die while I am stopped. Also, it feels like I have no power. I literally floored it and it slowly climbed to 30 mph before bolting forward. I just replaced all my vacuum lines since I was getting the engine code saying "EVAP leak large". I reset the computer, so at this point in time I don't have an engine code. I thought this would solve the problem, but it still idles rough. Mind you it doesn't always do this, only every now and then. I'm planning on pulling my throttle body off and cleaning it. Anyone ever experience this or have any suggestions? This is my daily driver, so I need it to run properly. Thanks for the help in advance.
Reply
Old Oct 30, 2013 | 08:25 AM
  #2  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

Anyone???
Reply
Old Oct 30, 2013 | 09:17 AM
  #3  
dwright98xj's Avatar
Member
 
Joined: Oct 2013
Posts: 211
Likes: 1
From: Chicago
Year: 1998
Model: Cherokee
Engine: 4.0
Default

To clarify, did this problem start after replacing the vacuum lines?
Reply
Old Oct 30, 2013 | 09:41 AM
  #4  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

No, this started before.
Reply
Old Oct 30, 2013 | 09:54 AM
  #5  
VTJeep's Avatar
CF Veteran
 
Joined: Jul 2010
Posts: 4,930
Likes: 3
From: 802
Year: 99
Model: Cherokee
Engine: 4.0
Default

leaks in the evap system can be tricky to detect, but this one sounds like it would be pretty easy. you can have the system fogged and it will show a leak. the other thought is that its tune up time. the first thing that comes to mind is the o2 sensor, but you need to go through the entire system and clean /replace what needs it. does it do it at WOT?
Reply
Old Oct 30, 2013 | 10:48 AM
  #6  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

What's WOT? Also, I replaced all the hoses and so far the check engine light isn't on. I would think that if it was an O2 sensor, the CEL would be on. I'm definitely going to clean the throttle body and I'm probably going to run some seafoam through it as well.
Reply
Old Oct 30, 2013 | 11:03 AM
  #7  
SteveMongr's Avatar
Beach Bum
 
Joined: Jul 2011
Posts: 6,123
Likes: 22
From: Cape Hatteras, North Carolina
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.0
Default WOT

WOT = Wide Open Throttle.
Reply
Old Oct 30, 2013 | 11:12 AM
  #8  
EZEARL's Avatar
CF Veteran
 
Joined: Aug 2009
Posts: 5,676
Likes: 301
From: WV
Year: '96
Model: Cherokee
Default

From what I've read about the diagnotic system in the '97 and newer XJ's not all O2 sensor problems (or some other sensor problems) set off the CEL. A scan tool should give the problem code/codes.
Reply
Old Oct 30, 2013 | 01:34 PM
  #9  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

Yes when I'm WOT I have no power. I leterally floored it and it took forever to get to 30 mph and then all of a sudden I had full power and the Jeep went forward fast. I've also noticed that I'll have the Jeep on cruise control and I can tell it struggles for power. Like I said, it only happens every once in a while.
Reply
Old Oct 30, 2013 | 03:51 PM
  #10  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

Here is a video that I recorded when it was running rough. Go to 26 seconds.
Reply
Old Oct 30, 2013 | 03:53 PM
  #11  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

It completely robs me of power and feels like it's going to die.
Reply
Old Oct 30, 2013 | 04:07 PM
  #12  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

My body is saying he thinks it's a bad coil.
Reply
Old Oct 30, 2013 | 04:14 PM
  #13  
EZEARL's Avatar
CF Veteran
 
Joined: Aug 2009
Posts: 5,676
Likes: 301
From: WV
Year: '96
Model: Cherokee
Default

Could be a number of things electrical and/or fuel supply related. I'd start with the free stuff first. Have it checked at your local parts store that gives free diagnostics. You want it scanned for codes and have them test the battery,starter,alternator,and charging system.
Reply
Old Oct 30, 2013 | 04:18 PM
  #14  
Coastie05's Avatar
Thread Starter
Seasoned Member
 
Joined: Jun 2012
Posts: 270
Likes: 0
From: Corpus Christi, TX
Year: 2001
Model: Cherokee
Engine: 4.0
Default

Will I still be getting codes if my CEL isn't on? My battery and starter are brand new.
Reply
Old Oct 30, 2013 | 04:23 PM
  #15  
EZEARL's Avatar
CF Veteran
 
Joined: Aug 2009
Posts: 5,676
Likes: 301
From: WV
Year: '96
Model: Cherokee
Default

I had a low idle problem recently that was caused by a dirty IAC and CTS. No CEL.

Both may be new but I'd want them tested under a load. And you don't want to get into randomly replacing parts.
Reply



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