Joined the 3.6 cylinder misfire club............

[DAVECS1]

look at the top of third gear. No misfires are shown. It sure felt like a misfire. Looking at the data it was just the throttle moving on it own under load.

Advertisement

 

[ShadowsPapa]

The TSB resets the adaptive learn and then slows down the adaptive learn. This keeps it from messing with the engine rating. Then they make the misfire monitor more tolerant. This will quell misfiring, not sure if it does it long term. The engine is set up to run LEAN.

I also have found the throttle dlictuates and causes what feels like a hesitation or misfire, but it isn't it is simply the throttle blades cyling during a steady state acceleration. I am fighting this on my tune right now.

They've been running things lean for decades and the further we go, the more they lean things out as far as absolutely possible without misfires and over-heating. Even in the 80s with carburetors we fought that lean condition - I'd "adjust" air bleeds of the BBD carb with a tiny awl to close them down and make other changes. They ran things on the very edge of misfire even back then. At least now they can monitor and keep it it slightly out of the danger zone.

 

[ShadowsPapa]

look at the top of third gear. No misfires are shown. It sure felt like a misfire. Looking at the data it was just the throttle moving on it own under load.

That's likely what my wife felt when she was driving her GC AFTER the TSB was performed. She said as it shifted it almost felt like a misfire, but it wasn't. She was trying to speed up to get into another lane and had some pressure on the throttle and she said it wasn't the shifting, but felt like the engine did a slight hiccup as it was shifting. She's normally pretty light-footed with her GC (thus the 26+ mpg LOL)
I told her that unless it felt like the misfires detected before - ignore it (because when I drove it after the fix, what I felt was a normal modern engine)

Anything new or different on the throttle signal "bouncing" you found?

 

[Gren71]

So the dealer drove it hooked up to their scanner and didnt see any misfires. They did find that apparently my 4wd system has an error code active, which jscan didnt pick up.

i scheduled to have the 4wd system work done, under warranty. And if the problem persists they said it should still be covered with

 

[DAVECS1]

I have managed to fix most of the oscilation in the throttle for most situations. It required going to a dyno and doing some adjustments to the timing and maximum brake torque angle setting in the torque management control. I am not sure what the issue in the picture is caused by, but I have seen it in two stock jeeps in second and third though not as severe as what mine does. I assume it is due to my supercharger hitting the limit with more gusto.

 

[ShadowsPapa]

So the dealer drove it hooked up to their scanner and didnt see any misfires. They did find that apparently my 4wd system has an error code active, which jscan didnt pick up.

i scheduled to have the 4wd system work done, under warranty. And if the problem persists they said it should still be covered with

At least you went in and had things reported and checked.
One my cables arrive to make it easier to connect and disconnect - I'll leave a scanner on mine and see how long I drive without misfires, or if any ARE recorded, how many and in what timeframe.

 

[ShadowsPapa]

I have managed to fix most of the oscilation in the throttle for most situations. It required going to a dyno and doing some adjustments to the timing and maximum brake torque angle setting in the torque management control. I am not sure what the issue in the picture is caused by, but I have seen it in two stock jeeps in second and third though not as severe as what mine does. I assume it is due to my supercharger hitting the limit with more gusto.

Love it.
Yeah, your "modified" jeep is likely to do more things or do them differently in that respect.

My wife said something about 4th to 5th but then I didn't realize she had her cluster set to show her the current gear....... odd to hear her say anything specific at all about a vehicle since she usually reports "it is broken" as the ultimate diagnosis.

 

[JeepCares]

So the dealer drove it hooked up to their scanner and didnt see any misfires. They did find that apparently my 4wd system has an error code active, which jscan didnt pick up.

i scheduled to have the 4wd system work done, under warranty. And if the problem persists they said it should still be covered with

Hey @Gren71 ! Sorry to hear about that. However, I'm glad you've gotten an appointment scheduled to get this properly addressed. Feel free to let us know if you need any additional support while working with your Jeep dealer. We'd be happy to look into it further for you!

Courtney
Jeep Cares