Misfire? at idle, but no engine codes
#11
JK Enthusiast
I had the same exact issue that started right around Christmas. I tried all the same things you did with no improvement. Last thing I tried was to replace the plugs with original equipment Champions. That took care of the problem for me. I was running E3s, then I read about someone saying that any plugs other than OE in the 3.8 people have had issues with. I figured it was cheap enough for me to try. Like I said, it took care of my issue and I have not felt the misfire since.
#12
Daughter took it to Jeep yesterday. They scanned it and no codes came up.
Told her to drive it and if it happens again pull over and call them to pick it up.
Told her it could be bad gas.
Hell, when I've got bad gas I just Backfire.
She's 400 miles away in college so I can't look at it.
Thank you Roadside and Warranty.
Told her to drive it and if it happens again pull over and call them to pick it up.
Told her it could be bad gas.
Hell, when I've got bad gas I just Backfire.
She's 400 miles away in college so I can't look at it.
Thank you Roadside and Warranty.
#13
JK Newbie
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Join Date: Aug 2012
Location: Dallas, TX
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Spark plugs on my 07 were shot after 50K miles. Electrode was worn down to a fine point on 5 of 6 cylinders. They weren't oily or burnt, simply worn out.
Symptoms came on slowly, the stick shift would wobble at stoplights. RPM would drop from 800 down to 400, stumble then float back up.
Then suddenly over 2-3 days it got bad, really rough idle when cold and stumbling under acceleration. Felt sluggish and slow all the sudden.
I thought I had bad fuel, maybe a clogged fuel filter, or worse OH GOD MY 3.8L must have a blown head gasket! Doom and gloom washed over me.
Nope, it was just plain old spark plugs.
Replaced all 6, she ran fine.
Actually ran quite a bit better. I just failed to notice the slow loss of power and poor gas mileage.
Symptoms came on slowly, the stick shift would wobble at stoplights. RPM would drop from 800 down to 400, stumble then float back up.
Then suddenly over 2-3 days it got bad, really rough idle when cold and stumbling under acceleration. Felt sluggish and slow all the sudden.
I thought I had bad fuel, maybe a clogged fuel filter, or worse OH GOD MY 3.8L must have a blown head gasket! Doom and gloom washed over me.
Nope, it was just plain old spark plugs.
Replaced all 6, she ran fine.
Actually ran quite a bit better. I just failed to notice the slow loss of power and poor gas mileage.
I had this happen recently. After seafoam and PCV valve I did a compression test and while doing the test discovered that one of the plugs had come loose. I decided to replace all the plugs and has been fine since. I've never had that happen before. It's worth checking.
I had the same exact issue that started right around Christmas. I tried all the same things you did with no improvement. Last thing I tried was to replace the plugs with original equipment Champions. That took care of the problem for me. I was running E3s, then I read about someone saying that any plugs other than OE in the 3.8 people have had issues with. I figured it was cheap enough for me to try. Like I said, it took care of my issue and I have not felt the misfire since.
#15
I am currently experiencing the same issues with engine missing under acceleration, no codes, no warning lasts about 10 seconds and it kicks back up. I have tried to reset back to factory specs, no change. I am stumped as to what could be the issue. only happens on partial throttle, any gear. Jeep will bog down, jerk like it's stalled and come back alive. It also does this stalling action when I cross railroad tracks with heavy bumps, like something electrical is loose, but I have checked and rechecked and found nothing.
I have also noticed my engine temps are running fairly high while sitting gets up to 222 degrees for a few minutes then once I take off it comes down to about 190. starting to think the water pump is shot as well.
could there be a connection here?
2012 jk sahara, 40k miles with 6 speed,
stock exhaust, stock air filter, 35's 3:21 gears, tuned with a traildash 1 to 93 performance tune on 93 octane, throttle tune performance, fan settings normal, tire size selected 34.75, gear selected 3.21.
I have also noticed my engine temps are running fairly high while sitting gets up to 222 degrees for a few minutes then once I take off it comes down to about 190. starting to think the water pump is shot as well.
could there be a connection here?
2012 jk sahara, 40k miles with 6 speed,
stock exhaust, stock air filter, 35's 3:21 gears, tuned with a traildash 1 to 93 performance tune on 93 octane, throttle tune performance, fan settings normal, tire size selected 34.75, gear selected 3.21.
#16
Thanks to everyone in this thread - same symptoms today with my 2010 Wrangler: keep tuned up, oil little dirty but full, 2 year old quality battery, did code check using 3 flicks of key & response was "none", checked all fluids - antifreeze very low so topped off. Will def check spark plugs.. hope that's solution. I have same issue with Jeep randomly not starting for 1 or 2 attempts - then perfect on 3rd. Intuition said bad gas, but will check one thing at time.
#17
hi all i was having same on my 2010 finally pulled plugs found 5 and 6 were completely warn out . so replaced wires and plugs much better for about a week now back acting up again but now when I first start I hear a exhaust leak I beleive but my milage has not changed much still around 20 . Im going pull plugs and check all holes and see if maybe one is loose.
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#18
2010 Wrangler Sport 4D - Clock Spring Replacement
THanks for sharing For past 5 or 6 years intermittently would not start, wait a few minutes.. then start. Last 2 years when this happened it wouldn't start at all & mechanics replaced battery 2 times! Two weeks ago jeep wouldn't start, tried jump & trickle, but full interior lights working etc and no start. Horn and signal lights had gone out few weeks prior after mechanic said they 'fixed' starting issue and was looking for new mechanic when Jeep died. Had towed to reputable mechanic and he diagnosed dead Clock Spring. Not sure if this is also related to air-bag recall, but would like to know if any Wrangler owners had Clock Spring issues - thanks!
#19
Super Moderator
Give it a good thrashing then use internal engine combustion chamber when it is hot, let cool, then go give it another good thrashing after about 1-2 hours of sitting. That gets rid of a lot of issues.