PDA

View Full Version : P0302 Cyl 2 misfire 4.0



muddeprived
12-21-2012, 08:30 AM
Another issue (6 total just this month LOL) popped up on the way to work. The CEL popped on and jeep starting rumbling. I was half way to work so I kept going and it started flashing and jeep ran like shit. Drove it back home the same way and pulled the codes, P0455 (the usual evap leak, gonna fix soon) and P0302 which is misfire cyl 2. I'm guessing the plug could be bad but what else should I be checking out? The coil rail was replaced four years ago (approx 17k miles) so I'm not really sure if that would go bad, but it could. Could this be fuel related? It's misfiring and CEL is flashing full time.

I had to jump start it yesterday cuz the battery was drained from sitting too long. Dunno if that had anything to do with it.


Thanks. You guys have been a huge help lately. :)

01 XJ 4.0 auto champion plugs

village_idiot
12-22-2012, 12:16 AM
a battery thats putting out less than ~12 volts can play havok with sensors. i would have a load test done, and have your alternator tested while your at it. dont drive it with a flashing CEL, that limp home mode.

muddeprived
12-22-2012, 03:42 AM
It's at a hair over 14v now unless my gauge is wrong.

Dragonslayer
12-22-2012, 06:02 AM
Disconnect the battery and clear the codes and see if it does it again then if it does and
if you feel like doing it: swap #2 injector with #3 injector and see if the code moves with the injector.
If not then I would try plugs, then I would say coil. Unless your PCM has a hiccup in it.

gauge isn't gonna tell you how good your battery is, that just basically tell's you that
your charging system is working properly.

like the idiot said above, have your battery "load" tested and that will tell you how
good your battery "REALLY" is. I would call around first to see who does LOAD testing,
I know autozone and advance don't unless they recently started.(doubt it)

muddeprived
12-22-2012, 09:08 AM
Disconnect the battery and clear the codes and see if it does it again then if it does and
if you feel like doing it: swap #2 injector with #3 injector and see if the code moves with the injector.
If not then I would try plugs, then I would say coil. Unless your PCM has a hiccup in it.

gauge isn't gonna tell you how good your battery is, that just basically tell's you that
your charging system is working properly.

like the idiot said above, have your battery "load" tested and that will tell you how
good your battery "REALLY" is. I would call around first to see who does LOAD testing,
I know autozone and advance don't unless they recently started.(doubt it)

I did clear the code and it still ran like a tractor until the code popped up a minute afterwards and started flashing again. Same code. Weather's kinda poopy to tear off the rail and switch stuff around so I'm gonna have to wait. Normally i'd drive it to my buddy's garage but it's running too crappy for me to risk it.

funnyguy595
12-22-2012, 09:44 AM
AAA does battery load testing.

Dragonslayer
12-22-2012, 12:55 PM
AAA does battery load testing.

seriously?????????????

village_idiot
12-22-2012, 01:41 PM
seriously?????????????
yeah, how do you think they sell so many batteries. my sister has also had them bleed brakes before.

Dragonslayer
12-23-2012, 06:20 AM
daaaaaaaamn

village_idiot
12-23-2012, 09:56 AM
daaaaaaaamn
http://www.youtube.com/watch?v=0iZOmjLrFMs

muddeprived
12-24-2012, 01:17 PM
Ok it was warmer today so i pulled the plug 1 and 2 (goddamn the 01 plug setup is a bitch to work with)...not the greatest quality pix and vid but i tried. (click on 2nd image for vid)

http://i693.photobucket.com/albums/vv294/Chriseatsmud/PIC-0003.jpg

http://i693.photobucket.com/albums/vv294/Chriseatsmud/th_MOV-0001.jpg (http://s693.photobucket.com/albums/vv294/Chriseatsmud/?action=view&current=MOV-0001.mp4)

Plug #2 is on the right. The top of the plug is all green and there's a little bit of burnt stains on the tip of the white part. The gap on both plugs seem the same and not worn like the old set.

muddeprived
12-31-2012, 02:09 AM
So i'm thinking coolant is leaking into cylinder two since that's the plug that's green. Could this be the head gasket failing?

village_idiot
12-31-2012, 10:26 AM
So i'm thinking coolant is leaking into cylinder two since that's the plug that's green. Could this be the head gasket failing?
worst comes to worst... 0331 head is trashed. they like to crack.

muddeprived
12-31-2012, 10:34 AM
Yeah probably. I was just out there putting the plugs back in and noticed yellow sludge on the underside of the oil fill cap. Poop.

This probably explains where my coolant's been going the past couple months.

Azzy
12-31-2012, 11:55 PM
Cooling system in a 4.0 is key... if you notice coolant going soemwhere, then its tiem to get the uv dye out and hope you just have a leak.

On the plus site, you can get a reman TUPY head for about $300.

muddeprived
01-01-2013, 12:39 AM
Cooling system in a 4.0 is key... if you notice coolant going soemwhere, then its tiem to get the uv dye out and hope you just have a leak.

On the plus site, you can get a reman TUPY head for about $300.

Got any info on this "tupy" head? Are they beefed up in the weak spots?

Azzy
01-01-2013, 10:00 AM
Some later XJs have an 0331 casting number on the head, these have weak spots, usually near cyl 3. The improved head was strengthened and has a casting mark of TUPY.

You can see some pics here: http://www.jeepstrokers.com/forum/viewtopic.php?f=5&t=480&start=45

Ive heard good things about Clearwater remans. Ive also heard from time to time they get backed up on orders.