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.

Rough running 4.0

Thread Tools
 
Search this Thread
 
Old 09-23-2009, 07:46 PM
  #1  
Newbie
Thread Starter
 
fbtased2002's Avatar
 
Join Date: Sep 2009
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Year: 1997
Model: Cherokee
Engine: 4.0
Default Rough running 4.0

I am running out of things to replace. I have a 94 4.0 that wont start unless you spray starting fluid in the throttle body and hold it wide open. Then once it is running if you throttle up to around 2500 it starts to run real rough? any ideas? I have changed every sensor and most other parts already. also I get a 42 code ( auto shutdown relay) when i check trouble codes
Old 09-23-2009, 11:03 PM
  #2  
Seasoned Member
 
1jeepman's Avatar
 
Join Date: Sep 2009
Location: Williamsburg, Ky.
Posts: 332
Likes: 0
Received 0 Likes on 0 Posts
Year: 1999 Sport
Model: Cherokee
Engine: 4.0
Default

have you changed the idle air control valve or map sensor? could be a vaccum leak causing it to run rough once started. i would look into that relay and replace that and see what happens.
Old 09-23-2009, 11:14 PM
  #3  
CF Veteran
 
91familyxj's Avatar
 
Join Date: Aug 2009
Location: Las Vegas
Posts: 1,263
Likes: 0
Received 0 Likes on 0 Posts
Year: 1996 Limited
Model: Grand Cherokee
Engine: 5.2
Default

How much fuel are you getting to the rail? Just trying to think of other things
Old 09-24-2009, 01:17 AM
  #4  
Newbie
Thread Starter
 
fbtased2002's Avatar
 
Join Date: Sep 2009
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Year: 1997
Model: Cherokee
Engine: 4.0
Default

I didn't replace the map or idle air sensors but I swapped them with my 94 YJ and it didn't make a difference. Also I checked the fuel pressure at the rail and the XJ is it 40 just like the book says, but the YJ is at 80. Thanks for the help by the way.
Old 12-16-2009, 03:05 PM
  #5  
CF Veteran
 
BillyBoy's Avatar
 
Join Date: Aug 2009
Location: Detroit, Michigan
Posts: 1,117
Received 30 Likes on 25 Posts
Year: 1998
Model: Cherokee
Engine: 4.0
Default

I'd check my plugs and wires to make sure they are in the correct firing order. I accidentally hooked two up in reverse on a Fiero (yes.... i actually had one....) I had. It did the same thing. A diagram should be easy to find.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Ye Ol' Cherokee
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
04-25-2017 08:35 AM
DanO55
MJ Comanche Tech. Stock & Modified.
2
09-02-2015 08:31 PM
David Chauncey Clothier
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
2
08-29-2015 09:31 PM
DanO55
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
1
08-28-2015 07:16 PM

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


Quick Reply: Rough running 4.0



All times are GMT -5. The time now is 04:18 AM.