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Engine studder and thottle lag anyone else having this issue

Ronnie S

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Yeah, I'm sure its FCA choking the motor, not the 300-1000lb weight difference between the Avenger and the Wrangler. Or the massive tire size difference.

A lot of these problems sound like detonation/octane is too low. I know the 3.6 is designed for low grade, but does anyone having these problems run premium?
Yep I have run shell vtech 93 octane for the last 6,000 miles. I still feel the kind of misfire when gently passing through 42 mph.
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9SecVmax

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Yeah, I'm sure its FCA choking the motor, not the 300-1000lb weight difference between the Avenger and the Wrangler. Or the massive tire size difference.

A lot of these problems sound like detonation/octane is too low. I know the 3.6 is designed for low grade, but does anyone having these problems run premium?
Well, reading back what I mentioned earlier, the Challenger is heavier than a 2-door Wrangler. The weight of a 20" wheel tire combo is close if not heavier on the Challenger than on my 2- Door sport. The Avenger example was a point referencing torque management. You have full throttle pretty much when you want. It is 400 lbs lighter, on average, than a 2-door wrangler.

Not sure If you are understanding or maybe I am not explaining. Torque management is an algorithm in the PCM to limit the motor's output regardless of the "requested" output via the pedal. TM is aggressively applied on the Wrangler. Just floor it in 2nd or 3rd gear and and the motor tone does not change. The throttle is not opening. PCM is saying NO. Anybody can look at the parameters used by the OEM with HP Tuners software. Anybody can buy it as well. I have a JL file. I thought it would be like tuning motorcycle ECU's. I was wrong. Its not even close. Raw tables are not exposed in most cases. Menu selections are made and all of these tables are interpolated. Some are accessible. It would take me weeks to figure it all out. Probably longer. TM is used to increase reliability. MOST people do not modify their Avengers/Caravans/Challengers. Even if they do, to NO where near the extent that Wrangler owners do. So, FCA CHOKES the motor to protect the drive line. TM is done via the throttle reduction, backing fuel off, 8 deg of timing retard OR a combination of all. Too many settings for me to understand.

My PCM is going to be sent out for a reflash as soon as I get it back from the dealer. That is the ONLY way to correct this. Not with throttle boosters. And, if you can gain a few extra ponies in the process, the better. It's not the 10 or 15 HP you will gain. You will barely feel it in a 2 ton tank. However, you will feel the increased drive-ability when TM is aggressively reduced and or eliminated.
 

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It sounds like this isn't happening though, which is leading to the detonation. At least that's what seems to be happening on this page.
My anecdotal evidence is with another car I have that would breakup in 4th gear at the drag strip. I had a pretty aggressive tune at the time. Running race gas (it was was tuned for 91) was a little better, but it would still breakup under that load. Totally killed ETs. Ultimately the fix was coil on plug and a more conservative tune.
It certainly sux that issues like this pop up frequently on brand new vehicles. That issue is unrelated to poor throttle response that I complain about. The JL is much worse than my 2013 JK was.

I would see if there are any DTC's in memory. Maybe you are getting multiple engine misfires. Ping (more apparent under load and in taller gears) could be octane/fuel or the mixture is leaning out. Vacuum leak is real common. I had to fix the older 3.5L because it did just that. I had an intake manifold gasket split. Was just enough to lean it out, make it ping and throw DTC's for misfire.

Maybe look around for a loose hose, intake clamps not tightened, EGR hose (if it has one). DTC's would point you in the right direction. Did the dealer help you at all? Being under warranty, you shouldn't have to worry about this at all. Are others having this same exact issue?
 

Kluk Ztopolovky

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Today I took the jeep for a spin without running the a/c andI noticed two things. !) the jeep is much faster without the a/c and 2) the rev's didn't stay up or increase between shifts actually drove like a normal manual. But I was surprised about the power difference from not having the a/c on.
Yes , I can feel as well how much engine power is transferred into the AC unit but it doesn't really effect the driving ability of the Jeep much , it has pretty potent and strong engine . I think many drivers today expect bit too much from their vehicles. It is a Jeep and not a Corvette and I think the 3.6 motor has more than enough horses.
 

SecondTJ

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MOST people do not modify their Avengers/Caravans/Challengers. Even if they do, to NO where near the extent that Wrangler owners do. So, FCA CHOKES the motor to protect the drive line.
Far more people modify their Challenger than Wrangler for performance. Majority of Jeep owners don’t mess with the ecu, they spend money on re-gearing.

The Pentastar is not known for its torque, I doubt it’s holding much back since the 2.0 makes more. Torque management is usually only for gears 1-2 where the multiplier is the highest.
 

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Cracker_Box

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More people need to try this. I wish I was more scientific about verifying this worked for me. But my commute this morning was 95% better this morning, however, maybe the Jeep was just in a good mood.

I can now cruise around parking lots at 1-1.5k rpms without working the clutch! My issue really did seem like 0-10% throttle was on/off. Now 0-2% is on/off, I might try progressively slower and progressively faster releases to see if I can reach perfection.
Thissssssss. Gonna try this out in the morning.
Have been 2800 miles in my 2dr 6spd.
Just got back from a trip to the smokies and did some gravel road trails in first and second most of the time... The freaking response when just trying to creep is disgusting. So much buck.

I'll update with my results.
 

Cracker_Box

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Ok. So it's been 2 weeks since I've done the throttle position sensor relearn.

Without a doubt this has helped tremendously.

I even did a study by not telling my girl about what I did then asked her to drive it for a day, then asked her if she noticed anything different.
She said " it was more smooth on take offs and creeping in parking lots" and I said w"you think that is??" Her response "I thought my clutch skills where getting better" hahah

Also noticed on the interstate that cruising in like 60-70mph in 5th gear my gas mileage is better.
 

Ronnie S

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Ok. So it's been 2 weeks since I've done the throttle position sensor relearn.

Without a doubt this has helped tremendously.

I even did a study by not telling my girl about what I did then asked her to drive it for a day, then asked her if she noticed anything different.
She said " it was more smooth on take offs and creeping in parking lots" and I said w"you think that is??" Her response "I thought my clutch skills where getting better" hahah

Also noticed on the interstate that cruising in like 60-70mph in 5th gear my gas mileage is better.
What did you do?
 

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Ronnie S

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No sir. Everything is working just fine.
I just might try this. As soon as I get my Jeep back together from the rain storm. Damn thing is airing out. :-(
 

Titanicon

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Curious - Anybody tried emailing a Jeep and/or FCA exec about this issue and the complete lack of ownership much less resolution from their dealer network?

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bwright1818

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I have given up with FCA, for now. I believe that this problem is well known, not only to us but to FCA. I believe they let them out the door knowing full-well, there was a problem. I believe they may never do a thing about it because of the small percentage of manuals vs. automatics. They can mask the problem in automatics to some extent by playing with the shift points, which they have done. Nobody is going to help any time soon because not enough people complain about it or even are aware of it. I KNOW that an FCA tech rep drove my car and said, "I have felt better, I have felt worse, and we're not doing anything about it right now." FCA knows and they could give a crap less.

When I first reported the problem to my dealer, the general manager drove the car with me. He kept making slight throttle movements, on and off. I said, "NO, you have to hold the throttle STEADY." He said, yeah, yeah and kept doing the same thing. FINALLY, I made him hold it steady and the misfire occurred. He said, "Yup, there is something wrong here." In hindsight, I believe he knew already and was masking it by the way he was on and off the throttle, just slightly. I have now found that if I do this same thing...drive like an ass....that it is actually bearable to drive the vehicle. It isn't right but it helps.
 

Rishsd

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I too am having this surging issue. It seems to happen at low rpm> I have taken it to two different dealerships. One of the "reprogrammed" my transmission. The other one refused to look at it and said Mopar will only fix it when it completely fails :/ . I believe its a pedal issue. The reason I say the pedal is the issue is because the pedal commander fixed the problem on the OP when the OP put the PC in eco mode. The pedal is just a potentiometer. If Jeep would add an ECO mode within the program either as a push button or through the dash menu I believe the problem would go away.
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