Temporary Misfire issues - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 04-20-2011, 01:58 AM   #1
Jeeper
 
4x4junkie's Avatar
 
Join Date: Aug 2010
Posts: 73
Temporary Misfire issues

99 TJ 2.5 Liter , auto, 33" MTs 154k miles

Ok I have a weird problem not sure what it could be. When I start my jeep when it is cold like in the morning or after it's been sitting for awhile , it takes like 3 cranks of the ignition to Start.
Once it starts it shakes like hell, like a misfire , like 30-40 seconds later it stops shaking . It drives fine after that and it will start with one turn of the key once it is warmed up.
Is there something happening in the cylinder?, I know this isn't norm . it's been rebuilt and only has 8k miles on the rebuild.
Runs good ,ok power.
No overheating , no check engine light.
Is something loose??

Baffeled!
Attached Thumbnails
Click image for larger version

Name:	image-391354684.jpg
Views:	42
Size:	82.3 KB
ID:	46031  

__________________
Brian Ochoa
4x4junkie is offline   Quote Quick Reply
Old 04-20-2011, 06:01 AM   #2
Jeeper
 
Indy's Avatar
 
Join Date: Jun 2009
Location: Bay Area
Posts: 554
Check the spark plugs, distributor, rotor and spark plug wires.

If they are good then seems like your fuel anti-drain back valve took a dump. Try cycling the key on/off few times before starting the engine.

__________________
98 TJ 4.7 Stroker!!! Unichip tuner, HPD30/D44, 4.56, Detroit Locker in rear axle, 3.25RC SL, 1.25BL, 1MML, 35x12.50x15, Cager Softs 15x8, XRC10 winch, Rancho 9000XL shocks with wireless remote
Indy is offline   Quote Quick Reply
Old 04-20-2011, 11:42 AM   #3
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 32,374
Images: 2
X2 on the check valve inside the fuel pressure regulator likely leaking and being the most likely source of that problem. Also as suggested above, cycle the fuel pump on-off-on several times to help get more fuel up to the fuel rail so it won't misfire so long.

My TJ had the exact same symptom and replacing the fuel pressure regulator as shown below fixed it. RockAuto Auto Parts has them for around $80.

You have to drop the fuel tank (run it near empty first) to replace the fuel pressure regulator but it's not a bad job at all. Especially for an older TJ like yours that doesn't have near the smog-system related plumbing attached to the gas tank like my '04 TJ has. The below pics are from when I replaced mine earlier this year.
Attached Thumbnails
Click image for larger version

Name:	FuelPressureRegulator1.jpg
Views:	30
Size:	146.6 KB
ID:	46055   Click image for larger version

Name:	FuelPressureRegulator2.jpg
Views:	28
Size:	117.6 KB
ID:	46056  

__________________
When you have a choice, buy American.

Jerry Bransford is offline   Quote Quick Reply
Old 04-21-2011, 08:10 AM   #4
Jeeper
 
4x4junkie's Avatar
 
Join Date: Aug 2010
Posts: 73
Quote:
Originally Posted by Jerry Bransford
X2 on the check valve inside the fuel pressure regulator likely leaking and being the most likely source of that problem. Also as suggested above, cycle the fuel pump on-off-on several times to help get more fuel up to the fuel rail so it won't misfire so long.

My TJ had the exact same symptom and replacing the fuel pressure regulator as shown below fixed it. RockAuto Auto Parts has them for around $80.

You have to drop the fuel tank (run it near empty first) to replace the fuel pressure regulator but it's not a bad job at all. Especially for an older TJ like yours that doesn't have near the smog-system related plumbing attached to the gas tank like my '04 TJ has. The below pics are from when I replaced mine earlier this year.
Ok I'll look into it thanks
__________________
Brian Ochoa
4x4junkie 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:
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
If you are having shifting issues with your NV3550, look inside. mrcarcrazy TJ Tech Forum 77 11-09-2013 10:16 AM
Lifted driveline issues? GroundHawg JK General Discussion Forum 17 05-23-2010 04:05 PM
How Temporary is Temporary? schulzmc TJ General Discussion Forum 7 02-19-2009 10:08 AM
Runing rough, idle rough, cylinder #4 misfire spdrcrpete TJ General Discussion Forum 13 06-02-2008 01:32 PM



Download our Mobile App

» Featured Product

All times are GMT -5. The time now is 07:44 AM.



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