Misfire in cylinder one - 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 06-10-2014, 02:25 PM   #1
Newb
 
Jeephairdntcare's Avatar
 
Join Date: Mar 2014
Location: Wild and Wonderful, West Virginia
Posts: 12
Misfire in cylinder one

The check engine light came on in my 97 wrangler sport. I took it to advanced auto to have the code read. I was told it was throwing a code indicating that there was a misfire in cylinder one. I replaced the spark plugs, wires, distributor cap & rotor button (it hadn't been done for quite some time). It didn't clear the code. I went back to advanced and had them clear the code. It came back on two days later. I took it back and it's throwing the same error code. Has anyone had this happen? Could it be the distributor or the coil?

Jeephairdntcare is offline   Quote Quick Reply
Old 06-10-2014, 02:51 PM   #2
Jeeper
 
Blackhawk36's Avatar
 
Join Date: Jan 2014
Posts: 364
The distributor or coil is unlikely since the coil would through random misfires and a worn distributor would do the same thing. P0300 instead of P0301.

Blackhawk36 is offline   Quote Quick Reply
Old 06-10-2014, 04:24 PM   #3
Jeeper
 
DoubleOught's Avatar
 
Join Date: Feb 2014
Location: Nashville GA
Posts: 1,178
Welcome to the forum. I don't recall it ever happening to cyl no. 1 but my son's 97 Sahara would randomly misfire when we bought it and for about 2 years, all we would get was misfire codes. It finally got bad enough to give us a code (don't remember the number) that pointed to the crank position sensor. We replaced the sensor and that took care of the problem. Not saying this is it but might be worth checking. Good luck with it.
DoubleOught is offline   Quote Quick Reply
Old 06-11-2014, 10:13 AM   #4
ExtremeTerrain.com Sponsoring Vendor
 
XTRyan's Avatar
 
Join Date: Dec 2012
Location: Malvern, PA
Posts: 2,316
Quote:
Originally Posted by Jeephairdntcare View Post
The check engine light came on in my 97 wrangler sport. I took it to advanced auto to have the code read. I was told it was throwing a code indicating that there was a misfire in cylinder one. I replaced the spark plugs, wires, distributor cap & rotor button (it hadn't been done for quite some time). It didn't clear the code. I went back to advanced and had them clear the code. It came back on two days later. I took it back and it's throwing the same error code. Has anyone had this happen? Could it be the distributor or the coil?
My misfires ended up being the valves and I had the head rebuilt. You can try a leak down test to confirm that everything is mechanically sound and it is indeed another type of issue. Good Luck!

-Ryan
__________________
Ryan H. | ExtremeTerrain.com Off-Road Outfitters
Toll Free: 800-988-4605 | Mon-Fri 10AM-6PM EST
Free Shipping on Orders Over $75!
EARN UP TO $200 TOWARD YOUR NEXT PURCHASE!
PM me for our WranglerForum Discount Code (must have 25 posts) or Price-Matching!
GET YOUR FREE JEEP PARTS CATALOG!
XTRyan is offline   Quote Quick Reply
Old 06-11-2014, 03:35 PM   #5
Newb
 
Jeephairdntcare's Avatar
 
Join Date: Mar 2014
Location: Wild and Wonderful, West Virginia
Posts: 12
Thanks guys! Hoping whatever it turns out to be doesn't cost more than my jeep is worth! I'll keep y'all posted!
Jeephairdntcare is offline   Quote Quick Reply
Old 06-11-2014, 04:13 PM   #6
Jeeper
 
DoubleOught's Avatar
 
Join Date: Feb 2014
Location: Nashville GA
Posts: 1,178
Agree with XTRyan also that you should do a compression check. May have a burnt exhaust valve.
DoubleOught is offline   Quote Quick Reply
Old 06-11-2014, 04:55 PM   #7
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,462
Images: 2
I'll write more tonight but many 97-98 4.0L engines received a set of weak valve springs from a bad batch. They causes random misfires. Also, there's no need to have your codes read or cleared by an auto parts store or garage. Your 97 TJ can display it's own codes in the odometer by turning the ignition switch on-off-on 3 times within 5 seconds and leaving it in the On position... give it time to work. Your year will give a 43 code for that particular misfire. You'll also always get a 55 code as the last code displayed indicating no more codes follow.
__________________
When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 06-11-2014, 06:15 PM   #8
Jeeper
 
99GoldenSahara's Avatar
 
Join Date: May 2013
Location: Eastern Washington State
Posts: 252
Ok, my 99 TJ hasn't thrown any codes yet but my curiosity is maxed out. How does one "know" how to decipher which code means what?
99GoldenSahara is offline   Quote Quick Reply
Old 06-11-2014, 06:30 PM   #9
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,462
Images: 2
Quote:
Originally Posted by 99GoldenSahara View Post
Ok, my 99 TJ hasn't thrown any codes yet but my curiosity is maxed out. How does one "know" how to decipher which code means what?
Older TJs throw 2 digit codes which can be deciphered at
ftp://rtfm.mit.edu/pub/usenet/rec.an.../general/part3

Newer TJs throw 4 digit codes like P1234 which can be deciphered at Chrysler PT Cruiser computer codes

Unfortunately 99GoldenSahara, '98-99 (and possibly early '00) TJs can't read their own codes. '97 and 2000 and newer can. Something about Jeep was switching from OBD to OBDIII then which prevented those two model years from generating their own DTCs (Diagnostic Trouble Codes). You can get an inexpensive code reader for $70-80 or so from Harbor Freight Tools that plugs into the diagnostic port under your driver's side dash.

More on the problem with the valve springs. This problem can often be fixed by simply swapping the valve springs for the current replacement part numbers. The 'good' valve springs use the same p/n as the old valve springs (removed from the market) so just use the regular p/n when buying replacement springs. But if the weak valve springs caused the problem long enough, the valves and/or the valve seats have become burned which would then require a complete valve job. My problem was 90% cured with new springs... I only very rarely got misfires after replacing the springs. A friend of mine however required a complete valve job to completely fix his misfire problem.

And to reset codes, just disconnect the battery for 2-5 minutes. If the problem is still there however, the code will come back.
__________________
When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 06-12-2014, 01:56 AM   #10
Jeeper
 
99GoldenSahara's Avatar
 
Join Date: May 2013
Location: Eastern Washington State
Posts: 252
Thanks Jerry. I appreciate having that information and resource in the event of.....
99GoldenSahara is offline   Quote Quick Reply
Old 06-12-2014, 12:57 PM   #11
Jeeper
 
99GoldenSahara's Avatar
 
Join Date: May 2013
Location: Eastern Washington State
Posts: 252
One more thing to ask: since my 99 TJ hasn't thrown any codes yet, will codes show up in the odometer or do I just check periodically with the code reader I'm going to go get from Harbor Freight? I read in the forum so many threads about diagnostic codes signaling something going wrong and since my 99 is one of those "special" years I'm just wondering how I'll know it's throwing a code. Thanks again.
99GoldenSahara is offline   Quote Quick Reply
Old 06-16-2014, 06:58 PM   #12
Newb
 
Jeephairdntcare's Avatar
 
Join Date: Mar 2014
Location: Wild and Wonderful, West Virginia
Posts: 12
Thank you so much! So much information. I think I'm actually dropping my jeep off today at my mechanic. I can do some stuff like tune ups, oil changes, etc. But I don't know a thing when it comes to engine work. Hopefully it won't be too much work & it won't be too expensive! I'll let y'all know what it turns out to be! I really appreciate everyone's feedback!
Jeephairdntcare is offline   Quote Quick Reply
Old 06-16-2014, 07:02 PM   #13
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,462
Images: 2
Quote:
Originally Posted by 99GoldenSahara View Post
I'm just wondering how I'll know it's throwing a code. Thanks again.
Any unusual diagnostic codes will light the Check Engine indicator on the instrument cluster.
__________________
When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 06-16-2014, 11:49 PM   #14
Jeeper
 
99GoldenSahara's Avatar
 
Join Date: May 2013
Location: Eastern Washington State
Posts: 252
Thanks. Now I know what and where to look if my TJ throws me a code.
99GoldenSahara is offline   Quote Quick Reply
Old 06-17-2014, 10:21 AM   #15
Newb
 
Jeephairdntcare's Avatar
 
Join Date: Mar 2014
Location: Wild and Wonderful, West Virginia
Posts: 12
I just want to say thanks again to everyone who has posted their thoughts and feedback. I got a call from my mechanic today who said that it is a burnt valve. My worst fear. He knows that I don't have much money to dump into it right now so he said I could still run it. He said that it would still misfire and that I wouldn't get as much power.

I asked him about fixing it (which he doesn't do because he doesn't have a mill) but he said that I probably shouldn't worry about rebuilding the head because my bearings are going out and if I sink money into a new head I could run the risk of having to replace the whole engine in just a year or so. I'm pretty devastated. I'm praying I can still run it for a bit before something happens to it.
Jeephairdntcare is offline   Quote Quick Reply
Old 06-20-2014, 08:02 AM   #16
Jeeper
 
Join Date: May 2014
Posts: 33
I just went through this ~2 weeks ago. You'll want to identify the root cause of the burnt valve, it's usually a lean condition on that cylinder. Mine was from a cracked intake manifold creating a vacuum leak on that runner.

Head work was ~250 from the machine shop. Incidentals and gaskets would probably be another 250 or less. If you can borrow a cherry picker, you can do this work yourself with hand tools on the ground.

2003 TJ daily driver

If you choose to continue to drive it, I would disconnect the injector on that cylinder. Otherwise, you'll be polluting your oil with gas and accelerating wear on the rest of the engine. How did he determine your bearings are worn?
Five9Dak is offline   Quote Quick Reply
Old 06-24-2014, 12:26 PM   #17
Newb
 
Jeephairdntcare's Avatar
 
Join Date: Mar 2014
Location: Wild and Wonderful, West Virginia
Posts: 12
Five9Dak,

Thanks for the feedback! I wish I could do it myself but I know nothing when it comes to engine work. I'd have to find someone with the tools & know-how to do it for me. I'm surprised at the 250-500 price. I was anticipating the price tag to be much higher!

I'm currently just running my jeep as is. I wish I had more options but I really cannot afford another jeep or a new engine at the moment. The mechanic I take my jeep to replaced my oil pump within the past two years. I just recently replaced my sending unit (I had another thread about this a few months ago) it fixed my gauge from bouncing all around but I still have low oil pressure. He did a few diagnostic tests and he combined his findings with the 200,000 miles my jeep has and he came to the conclusion that my jeeps bearings are just wearing out.

I'm just afraid to sink a lot of money into having the valve fixed just to take the chance of having to eventually replace the engine. I'm really not sure what to do at this point except run it & save to get another jeep. It sucks bc I just LOVE my '97 and the new jeeps just don't compare to that old thing! Lol
Jeephairdntcare is offline   Quote Quick Reply
Old 06-24-2014, 08:25 PM   #18
Newb
 
Cannierdr's Avatar
 
Join Date: Jun 2014
Location: Mass
Posts: 14
Has your mechanic checked the injector ? Late nineties Chryslers were very problematic as sediment from the fuel lines clogged the injector inlets with silt and rust resulting in misfires and lean conditions .i had theses issues on my truck and customers vehicles ..worth a look just to rule that out
Cannierdr is offline   Quote Quick Reply
Old 06-25-2014, 07:51 AM   #19
Jeeper
 
Join Date: May 2014
Posts: 33
Sounds like you should find a donor engine and some locals to help you swap it out for beer / pizza.
Five9Dak is offline   Quote Quick Reply
Old 08-02-2014, 08:11 PM   #20
Jeeper
 
OMGJeepin's Avatar
 
Join Date: Feb 2013
Posts: 30
So after this P0301 Cylinder one Misfire Plaguing me for the past year going on/off, I have finally (I'm pretty sure) fixed my issue. I know this error can be caused by different things, but for me, it was a loose distributor cap. One of the bolts holding it down had stripped from the distributor it self and wouldn't stay put. I got locktite (Red) and placed it back in, and so far no more CEL!

Just as a back story I replaced plugs, wires, cap and rotor, all before finding this.
OMGJeepin is offline   Quote Quick Reply
Old 08-12-2014, 11:16 AM   #21
Jeeper
 
OMGJeepin's Avatar
 
Join Date: Feb 2013
Posts: 30
Just to finish this out, It turns out the wobble in the distributor cap most likely wasn't causing this as the p0301 error code came back on the next day. I looked into my coilpack and found that the cable and metal rod from the coil pack to the distributor were rusted out. Replaced the cable and put a bunch of dielectric grease in there, and what do you know, fixed the issue 100%.

Check your coilpack cable to the distributor yo.
OMGJeepin is offline   Quote Quick Reply
Old 08-12-2014, 11:32 AM   #22
Jeeper
 
WWJeepDaddy's Avatar
 
Join Date: Jul 2014
Location: Garden Grove, Ca
Posts: 36
Exclamation

What you can do that might save money is look for a wrecked TJ that is the same year with the same engine with lower mileage. Have it delivered to a mechanic of your choice and get them to swap them out. Always have a compression check or a record of a compression check before buying a used engine.

Quote:
Originally Posted by Jeephairdntcare View Post
Five9Dak,

Thanks for the feedback! I wish I could do it myself but I know nothing when it comes to engine work. I'd have to find someone with the tools & know-how to do it for me. I'm surprised at the 250-500 price. I was anticipating the price tag to be much higher!

I'm currently just running my jeep as is. I wish I had more options but I really cannot afford another jeep or a new engine at the moment. The mechanic I take my jeep to replaced my oil pump within the past two years. I just recently replaced my sending unit (I had another thread about this a few months ago) it fixed my gauge from bouncing all around but I still have low oil pressure. He did a few diagnostic tests and he combined his findings with the 200,000 miles my jeep has and he came to the conclusion that my jeeps bearings are just wearing out.

I'm just afraid to sink a lot of money into having the valve fixed just to take the chance of having to eventually replace the engine. I'm really not sure what to do at this point except run it & save to get another jeep. It sucks bc I just LOVE my '97 and the new jeeps just don't compare to that old thing! Lol

__________________
***Just Empty Every Pocket ***
WWJeepDaddy 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 10:13 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