Repeatable Stutter/Judder During Light Acceleration

[swtrailboss]

As one said these minimal number of misfires are no big deal but a change in fuel can excite the computer to give you info that you've never seen before. Since this is the first time you have watched your live data I'm guessing your truck does this on every drive. If you speak of a literal shutter after a shift in 3rd or 4th gear id question your dealer about a torque converter issue if it persists.

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[DAVECS2]

What RPM is it happening at? 2500 to 3000 is when the high lift part of the cam is engaged. If your oil is not in the best shape for a number of reasons, the cam phazer can be slow or fast. There is a cleaning cycle the engine auto runs on some operating systems but it is not en led on all jeeps. A dealer service tool or some of the aftermarket tools can run the phazer cleaning cycle. This will also cause the misfires described.

 

[Stan H]

I have a '24 Sport S with the 3.6L/8AT, and have around 9K miles now. Yesterday I had a weird issue come up where early into my stop-and-go commute (10 miles or so), I was lightly accelerating away from the last stop and after it shifted into 3rd or 4th (I'm not sure which), immediately after the shift I felt a noticeable stutter/judder, not really sure what to call it. Just a single "kick in the pants" kind of feeling. I thought that was weird, but wasn't too alarmed.

However, every acceleration from a stop for the rest of the commute did the exact same thing after the same shift. I only have the basic gauge cluster so can't see the gear, but I was counting them, and I think it was after 3rd gear, but it could have been 4th.

Anyways, I get to work and I leave the vehicle running and immediately plug in my OBD-II reader and connect JScan. No codes. Then after work I drive the same way home and try to recreate it, and it never once did it. However, I was running JScan with live data on the way home and the only thing notable I saw was that pretty much every cylinder had 1-4 misfires counted in less than 10 miles.

Is that cause for alarm? I had never watched or logged data before, so I honestly don't know what's normal. A google search brings up that any misfires are bad, but I didn't feel anything, so I don't know...

I was ready to drive straight to the dealership after work if the issue continued, but it didn't, so I didn't want to waste my time or theirs just for them to tell me they couldn't duplicate the concern. It also didn't happen on the way to work this morning, for what it's worth. One-time weird TCM glitch or something, maybe??

Sometimes if your moving real slight and on a downhill grade and your still giving fuel it can jump up to the next gear and sorta give you this shudder kinda feeling . I have seen mine do like a quicky shift 3,4,5th in just super short distance. With more skinny peddle the computer will stay in said gear at the time until the required torque amount that you have dictated via the skinny peddle is matched.
ie.. going up a grade and you put the skinny peddle down it drops to 4th and maybe rides it out to the top of the grade before shifting to 5th. So if your just coasting along and it was in 3rd then 4th or even 5th it can feel sorta weird as it tends to shift higher and higher while barely cruising.
I have ran into this in 25mph sections I typically will just go to manual side stay in 3rd or 4th and go either 25mph or 30mph and when I get out of said zone foot off the fuel and over into D. And away we go.

 

[bmpcamry09]

Guys,

I'm new to this forum and was sent here from the JL Wrangler forum. I've developed a tuning fix for this hestiation issue everyone is having. I discuss it at length on this thread:

https://www.jlwranglerforums.com/fo...g-what-jeep-won’t.163856/page-10#post-3380173

About to create a thread here for the same thing. I also talk about this issue and fixing it on my Youtube page:

https://www.youtube.com/@bmpcamry

 

[bmpcamry09]

Here is a quick screenshot from a datalog I did showing the same hiccup:

 

[gonemad]

Interestingly, my ‘25 Rubicon that had the hiccup, (as did my ‘24 Sport S traded at 8,000 miles) no longer has the hiccup, 6800 miles. I don’t recall when it stopped

 

[bmpcamry09]

Interestingly, my ‘25 Rubicon that had the hiccup, (as did my ‘24 Sport S traded at 8,000 miles) no longer has the hiccup, 6800 miles. I don’t recall when it stopped

There is what appears to be a “learn” area within the tuning for this same VVL system, so maybe it’s adapted to you a bit. It’s there, just not as noticeable. Running 87 octane also makes it less noticeable because the default spark timing is less so it takes less of a dip.

 

[NC_Overland]

My 2025 Rubicon did this exact same thing constantly since the day I bought it..... Search for some of my posts. Thought it was fuel at first and tried every different octane I could to no avail. I ended up trading it on a 2025 Mojave and have not had the issue since

That’s wild. What a waste of money.

 

[gonemad]

There is what appears to be a “learn” area within the tuning for this same VVL system, so maybe it’s adapted to you a bit. It’s there, just not as noticeable. Running 87 octane also makes it less noticeable because the default spark timing is less so it takes less of a dip.

It’s not noticeable at all now. Zero.

 

[bmpcamry09]

It’s not noticeable at all now. Zero.

That's awesome, thats the first I've heard of the issue going away for anyone.

 

[gonemad]

That's awesome, thats the first I've heard of the issue going away for anyone.

I do run Exxon 87 almost exclusively. I first noticed it on my ‘24 Sport S. When I’d turn onto the road to my street, it’s a half mile, straight, slight incline, and 20 yards after that turn, maybe in second or third gear it would just jolt like the on-off of a light switch, very fast. Instantaneous. So I googled it at the time 18 months ago. After much reading, no one seemed to know what it was, so I chalked it up to a "Jeep thing".

I had other issues with that Jeep so I traded it for a ’25 Rubicon. It did exactly the same thing... until it didn’t.

That stretch of road is my “test track”. I had a new 2020 Harley with pre-ignition issues on that stretch of road in hard acceleration. I knowingly voided the warranty with a tuner and a map provided by DynoJet because I knew Harley couldn’t do anything about it for reasons I won’t burden you with. My point is, I really do pay attention to that stretch of road and what my vehicles do there, due to past issues, on the bikes, and on the two Jeeps I bought recently.

I don’t think it was transmission related. Something in the tune.

I could be wrong, and perhaps mine is an outlier, but I’m pleased it’s gone.

 

[bmpcamry09]

I do run Exxon 87 almost exclusively. I first noticed it on my ‘24 Sport S. When I’d turn onto the road to my street, it’s a half mile, straight, slight incline, and 20 yards after that turn, maybe in second or third gear it would just jolt like the on-off of a light switch, very fast. Instantaneous. So I googled it at the time 18 months ago. After much reading, no one seemed to know what it was, so I chalked it up to a "Jeep thing".

I had other issues with that Jeep so I traded it for a ’25 Rubicon. It did exactly the same thing... until it didn’t.

That stretch of road is my “test track”. I had a new 2020 Harley with pre-ignition issues on that stretch of road in hard acceleration. I knowingly voided the warranty with a tuner and a map provided by DynoJet because I knew Harley couldn’t do anything about it for reasons I won’t burden you with. My point is, I really do pay attention to that stretch of road and what my vehicles do there, due to past issues, on the bikes, and on the two Jeeps I bought recently.

I don’t think it was transmission related. Something in the tune.

I could be wrong, and perhaps mine is an outlier, but I’m pleased it’s gone.

Well if it comes back, you know where to find me lol

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