warming up kicks, pops, and misses - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 05-16-2006, 12:43 PM   #1
Newb
 
Join Date: May 2006
Posts: 1
Thumbs down warming up kicks, pops, and misses

I have a 98 TJ 4.0 Sport- 92000 miles. after about 2-4 minutes of operation, it starts to kick back throught the breather, pop and loose power for around 4-5 seconds. once it does this, it runs fine. it usually does this when you first start driving. i have replaced wires, plugs, distributor cap and buttum. plus replaced throttle positioning sensor, fuel sending unit and had it put on the diognostic machine twice. even the dealers are clueless. i see that there is a "upstream" and "downstream" O2 sensor, but what does this mean, where is it and will this help. i also just had the catillitic converter removed...same problems. what do i do now?

phill_graham is offline   Quote Quick Reply
Old 05-16-2006, 01:50 PM   #2
IITYWTMWYBMAB

WF Supporting Member
::WF Administrator::
 
4Jeepn's Avatar
 
Join Date: Apr 2005
Location: Florence, KY
Posts: 10,015
Images: 5
Phill, welcome,

If you have CA emmsions you have 4 O2 sensors if not you have 2. One should be either just forward of the cat or behind it. THe other should near the pre-cat, at least I think that is what they are called,, looks like a big coke bottle below the manifold.

Did you check the fuel pump or fuel filter, as well as there connections. TJ's are known to have issue's with the wire pack at the fuel tank working their way out. Keep us posted on this.

__________________
79.96.85.00.01.97.00.97.93.97.95.94
CJ.XJ.CJ. TJ. TJ.ZJ. TJ.TJ. ZJ.ZJ.YJ. XJ
4Jeepn is offline   Quote Quick Reply
Old 05-20-2006, 10:03 AM   #3
Newb
 
Join Date: May 2006
Posts: 4
Thanks for your reply, I have replaced almost everything at this time.
phillip graham is offline   Quote Quick Reply
Old 05-23-2006, 11:24 AM   #4
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,489
Images: 2
The upstream 02 sensor constantly monitors the air-fuel mixture and the downstream 02 sensor makes sure the catalytic converter is working properly. When the upstream sensor goes bad, it causes poor performance and a dramatic loss of fuel economy. Nothing really happens performance-wise if the downstream 02 sensor goes bad. Either going bad will cause the Check Engine light to illuminate.

Have you had anyone read your engine's diagnostic codes? You might be able to read your own codes with the following procedure but understand that this ability was removed in late-model 1998 TJs and did not reappear until sometime after 2000.

Try this and see if you can get your engine to display any stored diagnostic codes... without starting the engine, turn the ignition key on-off-on three times within five seconds and after leaving the key in the 'on' position, wait. It can take 5-10 seconds so be patient at this stage. If the codes are going to display, they will start appearing in the odometer, together with the Check Engine light blinking as the codes appear. If it works, you will always at least get a '55' code which doesn't indicate anything except that it worked.

I'm thinking maybe a bad crankshaft position sensor but it's hard to tell at this point.
__________________
Remember that having a different opinion doesn't also require one to be a jerk when expressing it.

When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 05-24-2006, 08:10 AM   #5
Newb
 
Join Date: May 2006
Posts: 4
Thanks for your reply, were is the upstream 02 sensor located? and the downstream and if the catalytic converter isn't on the jeep anymore will this matter ?
phillip graham is offline   Quote Quick Reply
Old 05-24-2006, 11:09 AM   #6
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,489
Images: 2
The upstream sensor should be just below the exhaust manifold. The downstream sensor is screwed into a bung on the catalytic converter.
__________________
Remember that having a different opinion doesn't also require one to be a jerk when expressing it.

When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 06-21-2006, 02:36 PM   #7
Newb
 
Join Date: May 2006
Posts: 4
Jerry check this out, don't understand but now if I cut off the engine when it starts to backfire and start it back it runs fine. Whats happening?
phillip graham is offline   Quote Quick Reply
Old 06-21-2006, 03:18 PM   #8
coilovers are damn flexy
 
bluvikng's Avatar
 
Join Date: Mar 2006
Location: Texas
Posts: 3,260
Removing your CAT throughs off your 02 sensor. Is your check engine light always on?
bluvikng is offline   Quote Quick Reply
Old 06-22-2006, 12:03 AM   #9
Jeeper
 
409biscayne's Avatar
 
Join Date: Mar 2006
Location: Spokane , Wash.
Posts: 58
Crap , it didn't work on my '98 .
__________________
98 Wrangler Sport 6 cyl 5 speed ( Sold ).
409biscayne is offline   Quote Quick Reply
Old 06-22-2006, 10:21 AM   #10
Newb
 
Join Date: May 2006
Posts: 4
Engine light never comes on.
phillip graham is offline   Quote Quick Reply
Old 06-22-2006, 10:47 AM   #11
coilovers are damn flexy
 
bluvikng's Avatar
 
Join Date: Mar 2006
Location: Texas
Posts: 3,260
How long have you been driving it without the CAT? I am just curious as this may be the problem, or if you just need a good cleaning on your throttle body. How long has it been running like this?

bluvikng is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 07:16 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC