Bad misfire 4.0 - 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 Cherokee & Comanche Forums > XJ Cherokee Technical Forum > Bad misfire 4.0

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineFS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 11-19-2013, 03:50 PM   #1
mikehenya
Registered User
2004 LJ Wrangler 
 
Join Date: May 2010
Location: ohio
Posts: 7
Bad misfire 4.0

Just got a 2000 Cherokee w/ 4.0 , it made it 90 miles home but missed constantly. Ticking seems a little louder than normal. When I got home I changed plugs, new TPS and new IAC. It is running better, but I am constantly getting a "Cylinder 6 misfire. I did an oil flush and am currently running some Techron through it but the miss is still there. Fuel pressure is 45.

I have been driving it locally as much as I can, misfires all the time but also has 2 other symptoms:
It is slow to return to a normal idle
After driving for a little while it starts acting like it is hitting the rev limiter at bout 26-2800rpm's. I have seen these symptoms all over the net, but no solid resolution.
Any thought? Thanks!

mikehenya is offline   Reply With Quote
Unread 11-19-2013, 03:55 PM   #2
copmedic309
Registered User
1995 XJ Cherokee 
 
Join Date: Sep 2013
Location: Woodbury, NJ
Posts: 65
Try changing your coil pack and your CPS. See if that helps.
__________________
Ry.
Rather be tried by 12, than carried by 6.
copmedic309 is offline   Reply With Quote
Unread 11-19-2013, 06:52 PM   #3
mikehenya
Registered User
2004 LJ Wrangler 
 
Join Date: May 2010
Location: ohio
Posts: 7
From what I have been reading, the 3 coil rail, it will miss fire on 2 cylinders? Not sure if that is true though. I guess I will try CPS next...ugghh
mikehenya is offline   Reply With Quote
Unread 11-20-2013, 07:39 PM   #4
Kalali
Registered User
2000 XJ Cherokee 
 
Join Date: Apr 2012
Location: Ocean, NJ
Posts: 432
These symptoms do not match a bad coil pack or faulty cps. Aside from the misfire code other symptoms are more like a bad tps.
Kalali is offline   Reply With Quote
Unread 11-20-2013, 08:10 PM   #5
mikehenya
Registered User
2004 LJ Wrangler 
 
Join Date: May 2010
Location: ohio
Posts: 7
I changed the TPS right before posting. Anything else I should look at?
mikehenya is offline   Reply With Quote
Unread 11-24-2013, 07:11 PM   #6
mikehenya
Registered User
2004 LJ Wrangler 
 
Join Date: May 2010
Location: ohio
Posts: 7
Anyone?
mikehenya is offline   Reply With Quote
Unread 11-24-2013, 08:01 PM   #7
bigbill888
Registered User
1998 XJ Cherokee 
 
Join Date: Nov 2009
Location: michigan
Posts: 954
pull #6 plug and see what ya got going on.
__________________
96 ZJ Laredo, 4.0, 242, 230K
95 ZJ Limited, 4.0, 242, 140K
98 XJ Sport, 4.0, 231, 140K
All work well
bigbill888 is offline   Reply With Quote
Unread 11-24-2013, 08:10 PM   #8
mikehenya
Registered User
2004 LJ Wrangler 
 
Join Date: May 2010
Location: ohio
Posts: 7
Quote:
Originally Posted by mikehenya View Post
When I got home I changed plugs, new TPS and new IAC. Thanks!
Plugs just looked normal...
mikehenya is offline   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.