NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old March 14th, 2018, 19:02
FastEddie505 FastEddie505 is offline
NAXJA Forum User
 
Join Date: Mar 2018
Location: Michigan
Posts: 9
Replaced almost Everything

ive looked for quite a while now all over and cant find someone that is/was in my boat. just got into this 99 xj about a month ago now and have replaced both o2 sensors ( periviouse owner had cut front o2 sensor plug off so i had to wire it back together) , intake gasket , banks header , 4 hole injectors , iac/tps , plugs and wires valve cover gasket , new oil change , cleaned tb twice , new cts , jeep is straight piped. may be missing somthing but heres my problem .it idles rough feels like it has a miss but never thrown any codes for one , will blow black exuasht . and has a God awful poping/crackeling noise from exhuast between 2k-3k dose not do it above or below maybe not enough back pressure ?? cant figure out what is going on . starting cold is much easyier than after it is warm , some times i have to try two or three times . everyone says its the o2 sensors but this would be the third time ive replaced them.


forgot to mention that i also have a cel for the tps and iac system


first jeep and im all ready loving it!!!!
Reply With Quote
  #2  
Old March 14th, 2018, 19:04
FastEddie505 FastEddie505 is offline
NAXJA Forum User
 
Join Date: Mar 2018
Location: Michigan
Posts: 9
Re: Replaced almost Everything

oh wow forgot to edit all the bad spelling out of this i apologize.
Reply With Quote
  #3  
Old March 14th, 2018, 20:18
Dragonslayer Dragonslayer is offline
NAXJA Forum User
 
Join Date: Feb 2004
Location: Los Angeles
Posts: 282
Re: Replaced almost Everything

You need to check the O2 sensors while the engine is warm and running crappy while
using a code scanner with graphing capability (not just a code reader). You want to see
a series of rapid, sharp, peaks and valleys all along the graph. If you see any long flat
spots or dead gaps along the graph then chances are good that you have a problem in
the O2 sensor wire harness.

I had this exact problem that drove me nuts for several months, last year. Did the same
as you and replaced the O2 sensors, twice. No improvement. I got a scanning app on
my iPad (Dash Command) and I found that the graph for the forward O2 sensor had
long, random flat spots and dead areas.

Then, I checked the wire harness - from the O2 sensor connector - to the forward-most,
black harness connector at the ECM - using a beeping continuity tester (it's one of the
features on my digital multimeter).

I found a badly repaired, crimped, splice inside the corrugated O2 sensor wire harness
(by the previous owner) in the harness between the power steering pump and the
hard black plastic cover near to the thermostat housing. I cut away the crimp, twisted
and soldered the wires together, and double-heat shrink wrapped the splice - just as
recommended by the FSM.

No troubles since.

I now have 2 sets of almost brand-new NTK O2 sensors sitting around as spares.

1998 XJ, 2WD, 4.0L, automatic.
Reply With Quote
  #4  
Old March 15th, 2018, 09:36
FastEddie505 FastEddie505 is offline
NAXJA Forum User
 
Join Date: Mar 2018
Location: Michigan
Posts: 9
Re: Replaced almost Everything

Guess I could mention that at w.o.t it acts normal , will check out o2 sensor graph after work today. Could be a coil problem?
Reply With Quote
  #5  
Old March 15th, 2018, 17:18
tech1001 tech1001 is offline
NAXJA Forum User
 
Join Date: Oct 2016
Location: Los Angeles
Posts: 44
Re: Replaced almost Everything

Being it's a 1999 it should have a up stream and a down stream o2 sensors , does your xj have this ?
Reply With Quote
  #6  
Old March 15th, 2018, 17:48
FastEddie505 FastEddie505 is offline
NAXJA Forum User
 
Join Date: Mar 2018
Location: Michigan
Posts: 9
Re: Replaced almost Everything

Yes it dose just replaced both and I got a flat line for volts on both sensors. Also replaced cap and rotor seemed to help out just alittle
Reply With Quote
Reply


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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
89 Cherokee Laredo Auto 4.0L-replaced sensors replaced fuel pump good 1 day, now not TWiST2k OEM Tech Discussion 2 December 15th, 2011 20:31
Just replaced my starter Rogue Sport OEM Tech Discussion 2 November 8th, 2006 18:50
89 NOT starting Replaced CPS TPS.... againstherwill OEM Tech Discussion 36 December 4th, 2005 21:54
replaced thermostat and... ricot83 OEM Tech Discussion 9 November 30th, 2005 03:31
Replaced TPS, what else could it be? 89xjgrey OEM Tech Discussion 3 March 3rd, 2004 07:59


All times are GMT -7. The time now is 10:53.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014