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.

High idle issue, cant figure it out.

Thread Tools
 
Search this Thread
 
Old 10-02-2014, 09:19 PM
  #1  
Seasoned Member
Thread Starter
 
Jeepola's Avatar
 
Join Date: May 2012
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default High idle issue, cant figure it out.

I'm having an issue with high idle, cleaned the IAC, replaced the TPS, cleaned the throttle body (wasn't all that dirty), replaced the engine air temp sensor, and still idles high. The OX sensor was replaced about two months ago, and the CPS was replaced about two years ago.

The only engine codes I WAS getting, were 12 & 25.

It's fine when I do a cold start, and drives fine.

If I turn it back on after it's warmed up, that's when it starts acting up.

It down shifts hard into 1'st gear, and revs up to 1,200-1,500. I put it in neutral and/or park, and let off the break, it still revs high.

I'm at a loss right now and need some advice.

1995, 4.0, autotrans, all after market exhaust (just two months old).
Old 10-02-2014, 09:23 PM
  #2  
Newbie
 
clawdog60's Avatar
 
Join Date: Aug 2012
Location: land of ILL
Posts: 29
Likes: 0
Received 0 Likes on 0 Posts
Year: 1996 tudor,00 fodo, stock,stock
Model: Cherokee
Engine: 4.0
Default

Pretty much what mine is doing and no cel on mine
Old 10-02-2014, 10:49 PM
  #3  
Member
 
Gimmy's Avatar
 
Join Date: Sep 2013
Location: Thurston County WA.
Posts: 104
Likes: 0
Received 0 Likes on 0 Posts
Year: 1990
Model: Cherokee
Engine: 4.0 HO
Default

replace the IAC.

could be a vacuum leak. normally only the renix models had issues with the intake getting lose, but it is worth a check
Old 10-03-2014, 12:03 AM
  #4  
Seasoned Member
 
perez1989's Avatar
 
Join Date: Feb 2010
Location: Pharr, Texas
Posts: 272
Likes: 0
Received 0 Likes on 0 Posts
Year: 1989
Model: Cherokee
Engine: 4.0L
Default

Spray carb cleaner where the intake meets the head and see if it goes away. This will check for intake leak.
Old 10-03-2014, 04:20 PM
  #5  
Seasoned Member
Thread Starter
 
Jeepola's Avatar
 
Join Date: May 2012
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

I was getting code 25 thrown.

High idle issue, cant figure it out.-image-1545081731.jpg

So I started messing with the wires and could hear the idle drop back down. I wasn't getting a code this whole time till just now. I did the seafoam treatment and I have no vacuum leaks.

SHES IDLING NORMAL AGAIN! thanks for the input tho! Really appreciate it.
Old 10-03-2014, 06:48 PM
  #6  
CF Veteran
 
Roler's Avatar
 
Join Date: Jan 2012
Location: Australia
Posts: 3,098
Received 300 Likes on 249 Posts
Year: 1997 (RHD)
Model: Cherokee (XJ)
Engine: 4.0 ltr
Default

You " started messing with the wires" and the idle came down. Define messing.
Sounds like an electrical connection/wiring problem, and messing with it didnt fix it, it likely just temporarily made contact. Chase the cause for a permanent fix because it will be back...
Old 10-04-2014, 10:34 AM
  #7  
Seasoned Member
Thread Starter
 
Jeepola's Avatar
 
Join Date: May 2012
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

They were getting hit from being next to the fuel rail. Thanks to jeep for putting a harness directly across the manifold. So I took apart a small portion of the harness and separated the wires. It wasn't actually shorting out, they were getting hot and sending wrong signals.

High idle issue, cant figure it out.-image-3622066363.jpg
Old 10-04-2014, 10:35 AM
  #8  
Seasoned Member
Thread Starter
 
Jeepola's Avatar
 
Join Date: May 2012
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

Hot*
Old 10-05-2014, 11:22 AM
  #9  
CF Veteran
 
Roler's Avatar
 
Join Date: Jan 2012
Location: Australia
Posts: 3,098
Received 300 Likes on 249 Posts
Year: 1997 (RHD)
Model: Cherokee (XJ)
Engine: 4.0 ltr
Default

Could be the pic, but several wires seem to be spliced?
Old 10-09-2014, 07:26 PM
  #10  
Seasoned Member
Thread Starter
 
Jeepola's Avatar
 
Join Date: May 2012
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Model: Cherokee
Default

Ok, well I thought I solved the issue. I've re torqued the manifold bolts, cleaned the O2 sensor, even sprayed carb cleaner along the manifold gasket. I'm positive there isn't any air leaks.

I'm still getting codes 24/25 being thrown. I ordered a new TPS and MAT sensor connector to re wire the sensors. Seeing how code 25 says it's a short.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Blackcherokee290
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
27
07-26-2022 07:52 PM
nts07
Cherokee Chat
1
08-27-2015 08:59 AM
bornofscreams
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
2
08-24-2015 02:09 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


Quick Reply: High idle issue, cant figure it out.



All times are GMT -5. The time now is 03:15 PM.