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2021 JL Throttle Surge (manual trans)

Rubi6mt

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2021 JLUR 6-speed. Mine has the same rev hang and occasional rough idle. TBH doesn't bother me. Coming to a stop/traffic light i double declutch down the gears to 2nd and then clutch in, which is when i get that rev hang. At that point, i'm already stopped so i don't pay attention to the rev hang.

On the rough idle, i get the occasional stumble and rev "loping" but I have that in my other cars as well and doesn't bother me.

Unfortunately we live in a highly restricted EPA world where they have to keep the emissions squeaky clean.
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DarkAardvark

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I normally heel toe / foot roll when I downshift to rev match. I figured the Jeep was just rev matching for me

For me, it seems to happen when I'm going in 4th and start slowing down for a stop. Take it out of gear, it blips the throttle, then put it in 3rd or double clutch to 2nd and come to a stop.

It only does it once and won't blip the throttle a second time (4th -> blip -> 3rd -> 2nd, not 4th -> blip -> 3rd -> blip -> 2nd)

I figured it was just trying to rev match. Doesn't bother me much, since I'd be doing it anyways
 

Ridgway Jeeper

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I have actually really been watching for this behavior on my wife's 21 JLR manual. It seems to be a pretty common issue on most newer drive by wire vehicles. My Raptor used to cycle rpm engine braking down steep trails. It would hold for a few seconds, then the rpm would run up by 1000-1500 for a few seconds then close the throttle again by itself and engine brake again bringing the speed back down. Super annoying and nothing you can do.

The JLR hasn't done any pf this yet and I have had it on the trails a couple of full days. I don't get any rev hang on shifts or rpm surging, I do have the gear position indicator and the rough idle.

I wonder if something like a pedal commander fixes this? It gets in the loop between the pedal and TB. Maybe it would eliminate the hang and surge by taking factory throttle plate manipulation out of the equation?
 

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Beaching631

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I got my JLUR in December of 2018 and noticed right away that slowing to a stop at a traffic light, etc causes the RPM to go so low it almost stalls once I get down to about 5-10mph. This happens in both neutral, and downshifting from 2nd gear back to N. At the same time the engine makes a weird sputtering noise that almost makes the vehicle sound like a diesel. It only happens for a second or two though. Is this what you guys are referring to? In the old days you could just mess with the idle, but I don't know how to do that in a "drive-by-wire" scenario.
A lot of people on these boards know a lot more about engines and transmissions than I do: is this something that is going to cause a huge repair bill down the line? If not, I've learned to live with it...just like the weak clutch.
 

R00STER

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2021 Sahara here with the same rev behavior.
Just picked up my 2021 Rubicon on 28Jun2021. I can't seem to replicate the rev hang described here. Granted im still im the break in period, but at least from 1-4 and 4-1, my rpms drop as soon as I let off the throttle. Maybe it was a late year correction.
 

buzzdoc

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Is it rev matching? I haven’t paid attention to it so far in my first 128 miles, but many newer manuals rev match when down shifting to make the transition more smooth. I know my buddies’ C7 vette did it.
 

Ridgway Jeeper

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Is it rev matching? I haven’t paid attention to it so far in my first 128 miles, but many newer manuals rev match when down shifting to make the transition more smooth. I know my buddies’ C7 vette did it.
No such thing on the Wrangler
 

Ridgway Jeeper

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Just picked up my 2021 Rubicon on 28Jun2021. I can't seem to replicate the rev hang described here. Granted im still im the break in period, but at least from 1-4 and 4-1, my rpms drop as soon as I let off the throttle. Maybe it was a late year correction.
Mine was built mid May and has 1500 miles on it now. Doesn't do this either.
 

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R00STER

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I have double checked, and I do not have rev hang.

Also, I noticed that the ESS must not be engaged by default on my 2021 rubi with a manual. I have verified that all conditions for the ESS have been met and still nothing.

Are others seeing this or is this a glitch?
 

MountiesNGamecocks

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Thank you for checking. It looks like I get a field trip to a Jeep service department… yay 😔
 

Robby Robot

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I have a 2022 JLR that was delivered in June. The throttle surges to 2500 - 3000 rpm when going to neutral for a few minutes after cold start. I've read on some forums that it has cause their Jeep to "lurch through stop signs" but I haven't seen it that pronounced, though I have felt it lurch if it revs when I engage a gear. I seem to remember seeing an engineering-related article a while back that this is a routine in the ECU that forces the engine to warm at start up. Haven't been to the service center about it yet (been resolving electrical issues) but it's annoying AF when I pull to a stop light and pedestrians think I'm threatening to run them down when the engine revs.
 

boarder140

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I have a 2022 JLR that was delivered in June. The throttle surges to 2500 - 3000 rpm when going to neutral for a few minutes after cold start. I've read on some forums that it has cause their Jeep to "lurch through stop signs" but I haven't seen it that pronounced, though I have felt it lurch if it revs when I engage a gear. I seem to remember seeing an engineering-related article a while back that this is a routine in the ECU that forces the engine to warm at start up. Haven't been to the service center about it yet (been resolving electrical issues) but it's annoying AF when I pull to a stop light and pedestrians think I'm threatening to run them down when the engine revs.
Same thing with mine as well - 2022 JLUR.
This rarely happens if I let the idle fall under 1k rpms after initial start before I move
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