Jeep Cherokee Forum

Go Back   Jeep Cherokee Forum > Technical Discussion > OEM Cherokee Tech
Register Forgot Password?
Register Photos FAQ Members List Social Groups Search Today's Posts Mark Forums Read GarageVendor DirectoryvBLive TSB & Recalls
Search

Welcome to Cherokee Forum!
Welcome to Cherokee Forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
 
 
submit to reddit
 
Thread Tools Search this Thread Display Modes
Old 05-09-2011, 12:01 AM   #1
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default 92 4.0 accel studder and intake backfire

Hi all, I have a 92 Cherokee sport 200k mi 5 speed. Recently I have noticed a slight studder under acceleration anywhere from 25 mph all the way to 75 mph. It happens most around 45 mph. Also sometimes when the studder occurs I get a backfire through the intake. I have replaced my fuel pump and filter. I have under 5k miles on new plugs and wires. I just cleaned up the cap an rotor as well. I have good fuel pressure. Anyone know what could be causing this problem? As an added note...the jeep feels very sluggish and does not feel like it has the power it use to have.
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 12:09 AM   #2
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

Quote:
Originally Posted by 92jeepxj
Hi all, I have a 92 Cherokee sport 200k mi 5 speed. Recently I have noticed a slight studder under acceleration anywhere from 25 mph all the way to 75 mph. It happens most around 45 mph. Also sometimes when the studder occurs I get a backfire through the intake. I have replaced my fuel pump and filter. I have under 5k miles on new plugs and wires. I just cleaned up the cap an rotor as well. I have good fuel pressure. Anyone know what could be causing this problem? As an added note...the jeep feels very sluggish and does not feel like it has the power it use to have.
Also forgot to mention that the studder happens only under 3k rpm. Most prominent right under 2k
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 12:14 AM   #3
CF Veteran
 
Join Date: Nov 2010
Location: North Carolina
Posts: 1,274

View HCCAFan's Photo Album My Photos
1999 Cherokee
Default

Set your timing. It's off.
HCCAFan is offline   Reply With Quote
Old 05-09-2011, 12:24 AM   #4
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

Isn't the 91 Cherokee timing not adjustable?
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 12:24 AM   #5
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

Woops 92 I mean
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 12:33 AM   #6
CF Veteran
 
Join Date: Nov 2010
Location: North Carolina
Posts: 1,274

View HCCAFan's Photo Album My Photos
1999 Cherokee
Default

It can definitely jump timing via the chain.
HCCAFan is offline   Reply With Quote
Old 05-09-2011, 12:35 AM   #7
CF Veteran
 
Join Date: Nov 2010
Location: North Carolina
Posts: 1,274

View HCCAFan's Photo Album My Photos
1999 Cherokee
Default

Saw someone saying a lean condition can cause an intake backfire. Not sure how though.
HCCAFan is offline   Reply With Quote
Old 05-09-2011, 12:39 AM   #8
CF Veteran
 
Join Date: Nov 2010
Location: North Carolina
Posts: 1,274

View HCCAFan's Photo Album My Photos
1999 Cherokee
Default

Related to this?
http://www.cherokeeforum.com/f2/putt...ackfire-56846/
HCCAFan is offline   Reply With Quote
Old 05-09-2011, 12:55 AM   #9
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

I'll check my timing tomorrow at work. Also will try the deadpan and see how that does
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 12:56 AM   #10
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

I'll check my timing tomorrow at work. Also will try the seafoam and see how that does.
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 12:57 AM   #11
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

That doesn't really sound like the problem I'm having but the seafoam is worth a shot
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 01:15 AM   #12
CF Veteran
 
Bustedback's Avatar
 
Join Date: Feb 2010
Location: Oroville, CA
Posts: 9,671

View Bustedback's Photo Album My Photos
1995 Grand Cherokee
Default

You may have a plug wire or boot letting the spark leak out, could have carbon tracking inside the dist cap, or could have a couple wires cross firing. The timing should be ok if you never dinked with the distrbutor, and a jumped chain would cause a problem at any RPM if the engine even started.
__________________
Steering stabilizers will not cure or cause death wobble, they only mask the real problem that is causing death wobble. Oil pumps do not make pressure, they create flow. Bearing clearence and restrictions make pressure. It's the crank sensor.
Bustedback is offline   Reply With Quote
Old 05-09-2011, 01:22 AM   #13
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

I went out at 1 this morning to the darkest back road I could find. Turned my lights off and opened the hood...no spark jumping at all. I also pulled the plugs one at a time to check engine idle and speed...all were good. Also I just cleaned out the distributor and rotor (cleaned the wear off the points). Could this be an O2 sensor problem?
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 06:24 AM   #14
CF Veteran
 
Join Date: Nov 2010
Location: In the middle of Minnesota!
Posts: 4,625

View tjwalker's Photo Album My Photos
1999 Cherokee
Default

A backfire occurs when there is an imbalance in the air to fuel ratio required for your vehicle to operate properly. Yes, a lean condition can cause backfires in the intake.

Unless you have verified fuel pressure with a gauge, you're guessing if you have proper fuel delivery. Regulator still in play here. Be sure that your pressure is within factory SPEC. A gauge is the only way to be sure you're not chasing your tail here.

The backfire solution usually involves checking for vacuum leaks, and ensuring the fuel system is functioning properly.

Other things to consider if you have no vacuum leaks and fuel delivery is within spec: Ensure that your ignition is solid. You mention new plugs and wires and that you cleaned the cap and rotor. I would replace the cap and rotor. They aren't designed to be cleaned, and aren't expensive to replace. They can have cracks in them that you can't possibly see. Oxygen sensor can be responsible as well if they fail in a certain way. They have a finite lifespan between 100k and 150k, depending on the efficiency of the engine.
__________________
Without data, all you have is an OPINION!

Past Jeeps: '49 Willys, '81 Scrambler, '88 Comanche

Current Jeep: 1999 XJ Sport, bone stock, daily driver.

I work on Jeeps!!

Last edited by tjwalker; 05-09-2011 at 06:40 AM.
tjwalker is offline   Reply With Quote
Old 05-09-2011, 10:19 PM   #15
Member
 
92jeepxj's Avatar
 
Join Date: Mar 2010
Location: Colorado
Posts: 125

View 92jeepxj's Photo Album My Photos
1992 Cherokee
Send a message via Yahoo to 92jeepxj
Default

Well I unplugged my o2 sensor for the drives today and it actually drove fine! No sluggishness and no stuttering at all. So should I automatically point my finger at the o2 sensor?
92jeepxj is offline   Reply With Quote
Old 05-09-2011, 10:19 PM
 
 
 
submit to reddit
Reply
Go Back   Jeep Cherokee Forum > Technical Discussion > OEM Cherokee Tech



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

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Jeep backfire in intake and hesitation in accel VARG7 OEM Cherokee Tech 43 06-12-2012 11:07 PM
engine miss or studder 84wagoneer OEM Cherokee Tech 1 12-01-2009 10:27 PM
dist. shaft end play/ backfire through intake. SoCo_Fox OEM Cherokee Tech 13 10-13-2009 01:12 PM
backfire thru the intake claygrassmann OEM Cherokee Tech 13 07-14-2009 11:51 PM
Random dying or studder djames56 OEM Cherokee Tech 3 11-30-2008 03:35 PM


All times are GMT -5. The time now is 02:35 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.5.2
This site is in no way affiliated with Jeep or Chrysler.

Emails Backup