Survey- For those with misfire issues

[ChrisNLA]

Welp. My '22 Sport S built in July did it. Has 1,580 miles on it.

Pulled out of my girlfriends driveway, heard a ding and the engine light came on, then another ding and it started flashing. Slowed to a stop and it was running very rough, so started to back into a driveway and drive back to her place. As I throttled up over 1,500 RPM all shuddering stopped and it went back to running smooth. CEL stayed solid. Drove back to her place and got my scanner out. P0300.

Drove it home 35 miles with engine light on, didn't seem to have any issues. Engine sounds same as it ever has. At home I disconnected battery, checked that the ECM connectors were fully seated, looked for any obvious things (loose connections and hoses) and reconnected the battery. Went down the road and put it through three more key cycles - upon the third key cycle the light was off.

Perhaps unrelated, but the first tank of gas was regular 87 (dealer filled it up). The next three were premium 93 (habit from my SS Camaro I drive a lot). Fourth tank was back to 87 since my girlfriend was filling it up and I was gonna save her some money. Less than 20 miles after that fill up - throws a P0300.

Anyway, I am ordering another dongle so I can run JScan or something similiar that I can see individual misfires with. Gonna keep on driving.

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[Snook]

Well it finally happened again, flashing CEL. We’re at 6700 miles now , the first time it happened was back in June at 2300 miles. Identical situation as the first incident. Drove the Jeep in the morning to and from church (very short distance, less than a mile.) decided to go to lunch, no issue, after lunch(approx 1 hour) Flashing CEL comes on briefly as we drive away from the restaurant. Truck never ran rough. Continued on to our second stop. wife stayed in the car so I left it running, then drove home. Decided to let it sit for awhile and see if the light would come on when I started it again. The CEL came on and stayed on when I drove it around the block. Never once ran rough. I’ll take it to the dealer and let them check the code, I’m sure it will be the same P0300.

 

[ShadowsPapa]

Welp. My '22 Sport S built in July did it. Has 1,580 miles on it.

Pulled out of my girlfriends driveway, heard a ding and the engine light came on, then another ding and it started flashing. Slowed to a stop and it was running very rough, so started to back into a driveway and drive back to her place. As I throttled up over 1,500 RPM all shuddering stopped and it went back to running smooth. CEL stayed solid. Drove back to her place and got my scanner out. P0300.

Drove it home 35 miles with engine light on, didn't seem to have any issues. Engine sounds same as it ever has. At home I disconnected battery, checked that the ECM connectors were fully seated, looked for any obvious things (loose connections and hoses) and reconnected the battery. Went down the road and put it through three more key cycles - upon the third key cycle the light was off.

Perhaps unrelated, but the first tank of gas was regular 87 (dealer filled it up). The next three were premium 93 (habit from my SS Camaro I drive a lot). Fourth tank was back to 87 since my girlfriend was filling it up and I was gonna save her some money. Less than 20 miles after that fill up - throws a P0300.

Anyway, I am ordering another dongle so I can run JScan or something similiar that I can see individual misfires with. Gonna keep on driving.

Octane has zip to do with low rpm misfire.

 

[ChrisNLA]

Octane has zip to do with low rpm misfire.

I didn't suspect so. Regardless - I thought the coincidence was amusing.

Drove it to work today - no worries. Guess I'll join the gang of keeping a data logger nearby and participate occasionally on the Gladiator game show 'When will we misfire next?!'.

 

[Snook]

I didn't suspect so. Regardless - I thought the coincidence was amusing.

Drove it to work today - no worries. Guess I'll join the gang of keeping a data logger nearby and participate occasionally on the Gladiator game show 'When will we misfire next?!'.

My view is, if it’s running well I’m not going to sweat it. I’ll just take mine over to the dealer, have them check the code and clear it. If they want to keep it and trouble shoot it fine. If not I’ll keep driving it and keep my log of incidents.

 

[Snook]

I still enjoy this truck far more than my 4Runner.

 

[Snook]

Octane has zip to do with low rpm misfire.

How’s your new one running? Are you still having issues?

 

[ChrisNLA]

My view is, if it’s running well I’m not going to sweat it. I’ll just take mine over to the dealer, have them check the code and clear it. If they want to keep it and trouble shoot it fine. If not I’ll keep driving it and keep my log of incidents.

About the same attitude here. The misfire incident wasn't overly concerning and resolved it self almost immediately - so, unless it becomes a common occurrence or something else changes noticeably (such as smoothness of engine running) then this is pretty much and observe and report item.

 

[Maximus Gladius]

I didn't suspect so. Regardless - I thought the coincidence was amusing.

Drove it to work today - no worries. Guess I'll join the gang of keeping a data logger nearby and participate occasionally on the Gladiator game show 'When will we misfire next?!'.

The outcomes all seem to vary when a misfire happens, from just seeing numbers on a data sheet to full on loosing power when it’s needed, like passing on the freeway.

Mine felt like shaking apart when I stomped on the throttle to pass. It wasn’t a life and death thing but if I had to get around quick and that’s when the engine decides to quit, then it causes some major concern.

For those that just get numbers on a data sheet, you’re lucky.

 

[ChrisNLA]

The outcomes all seem to vary when a misfire happens, from just seeing numbers on a data sheet to full on loosing power when it’s needed, like passing on the freeway.

Mine felt like shaking apart when I stomped on the throttle to pass. It wasn’t a life and death thing but if I had to get around quick and that’s when the engine decides to quit, then it causes some major concern.

For those that just get numbers on a data sheet, you’re lucky.

Definitely curious to see where it tries to do this again, if ever. This was at very low RPM on street with a 25 MPH speed limit. I haven't been afraid to let this engine sing a little and it's never gave me cause for concern at high RPM. I am interested to see where this goes - but I am going to begin capturing data now just to see what it looks like even when it's not acting up.

 

[Snook]

Definitely curious to see where it tries to do this again, if ever. This was at very low RPM on street with a 25 MPH speed limit. I haven't been afraid to let this engine sing a little and it's never gave me cause for concern at high RPM. I am interested to see where this goes - but I am going to begin capturing data now just to see what it looks like even when it's not acting up.

Both of my flashing CELs were at very low rpms, basically slowly driving out of parking lots.

 

[ShadowsPapa]

How’s your new one running? Are you still having issues?

Mine is only idle and low speed after having been shut off for a few minutes. It comes out of it with throttlw or after running a minute or so. Almost like a heat soak thing after shutting down. Fine when cold!
It's rare and only under very specific conditions. But it's bad wbenvit happens spooky for a few moments.

 

[Snook]

Mine is only idle and low speed after having been shut off for a few minutes. It comes out of it with throttlw or after running a minute or so. Almost like a heat soak thing after shutting down. Fine when cold!
It's rare and only under very specific conditions. But it's bad wbenvit happens spooky for a few moments.

Do you get the flashing CEL, or solid?

 

[ShadowsPapa]

Do you get the flashing CEL, or solid?

Yes.
That's the short answer.

Otherwise, the first time in July, it was dinging and flashing, then stopped flashing and then after a second or two, set it solid.

This time, a couple of days ago, it was dinging a little, flashed the CEL, then finally set it solid after it flashed for a while. The CEL went away on its own after a couple of shutdowns and restarts over the next day. It's been fine since.
it's very specific - drive it enough miles to get everything 100% warmed up.
Stop for maybe a meal, or some quick shopping, come out after 15-30 minutes and start it again and it MAY misfire. The CEL will flash, it will ding, and the CEL will finally come back on and stay.
It bucks and jumps - but if I "give it some gas", take it off idle into the mid-teens as far as RPM, it settles down or if you wait, it may settle down.
It's only idle or very low RPM and light load after sitting a few minutes. It's as if something gets warm from being shut down without fans running.
In the old days I'd call that "heat soak" when coolant temperatures are likely to jump due to the hot spots of the engine putting heat into the coolant but the coolant not being cooled by moving or the fans. Temperatures would actually rise way over the normal 190-200 degrees in older cars and trucks- maybe into the 230 or higher range where if you had a bad radiator cap the coolant would boil AFTER you shut it down because no more heat was removed from the coolant but hot engine parts were still heating the coolant in the block and heads.

 

[jebiruph]

Yes.
That's the short answer.

Otherwise, the first time in July, it was dinging and flashing, then stopped flashing and then after a second or two, set it solid.

This time, a couple of days ago, it was dinging a little, flashed the CEL, then finally set it solid after it flashed for a while. The CEL went away on its own after a couple of shutdowns and restarts over the next day. It's been fine since.
it's very specific - drive it enough miles to get everything 100% warmed up.
Stop for maybe a meal, or some quick shopping, come out after 15-30 minutes and start it again and it MAY misfire. The CEL will flash, it will ding, and the CEL will finally come back on and stay.
It bucks and jumps - but if I "give it some gas", take it off idle into the mid-teens as far as RPM, it settles down or if you wait, it may settle down.
It's only idle or very low RPM and light load after sitting a few minutes. It's as if something gets warm from being shut down without fans running.
In the old days I'd call that "heat soak" when coolant temperatures are likely to jump due to the hot spots of the engine putting heat into the coolant but the coolant not being cooled by moving or the fans. Temperatures would actually rise way over the normal 190-200 degrees in older cars and trucks- maybe into the 230 or higher range where if you had a bad radiator cap the coolant would boil AFTER you shut it down because no more heat was removed from the coolant but hot engine parts were still heating the coolant in the block and heads.

Maybe a bad sensor that's not recovering correctly from running hot to running cold.

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