Well i just got the latest software which im sure was V36 and it didnt seem to fix my stumble. When I did a normal take-off it revved to 2200 or so and then dropped a little and then went up again. Isn't that still a stumble?? It does see a little better but not cured. Maybe this is normal? Or is this not the stumble everyone is talking about? I was real excited about getting the fix, but im not sure it was a fix. I'll play with it some more and try some fast take-offs and see how it goes. :???:

 

As long as you have software intervening between the driver and the car, you will have imperfect behavior. V36, V37, whatever.

I've found that when I'm not "assertive" on the accelerator, I encounter the yo-yo effect. This makes it difficult to accelerate slowly and smoothly, which is what you might be experiencing.

When I'm very assertive, especially when trying to merge into traffic while exiting a parking lot, I encounter the stumble. This makes it very dangerous.

I think the problem is that the various software driven control systems have to contend with often conflicting inputs (eg, accelerator position/rate and wheel slip) and they sometimes end up doing something inappropriate.

The engineers can tweak software parameters to improve things but I think there will always be some unexpected and unwanted behavior.

 

Just picked up the CVT from having the DME flashed with v.36.04.01 and I still have the yo-yo at 10 mph and the push at 8 mph when braking. As such, I don't know if the same version will cure your surging or yo-yo on the MCS.

 

I don't think you have teh Yo-Yo... or at least what yoru expeirencign isn't teh yo-yo... now it is possible it was programmed in correctly, what you described sounds more like intial Lag that is just apparent in a CVT, CVT act very differnt especially when acceleratign hard or when using the simulated gears.... also try to not take it in to overaccel (pressing on the tip of the acelerator after you feel ressitence, which make the engine rev higher) when accelerating I bet you'd see your yoyo lag go away..it does seem to accel faster this way..

 

Actually, driving in stop and go traffic, the cvt gets very jerky at 10 mph. There is also a slight push when slowing @ 8 mph. The push feels like someone tapped you from behind.

The car does not display any of these symptoms under hard acceleration.

As for incorrect installation, I don't think this is so as the v.36 software was uploaded 3 different times. Maybe they were different sub-versions, I'm not sure.

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Despite what others may think, I'm here to help.

 

Well after further "testing" i think it is considerably better. Part of the problem was that i was so used to the stumble that i was letting off the gas and not even realizing it. Seems to be better but i still need more testing before i can call it a fix like the other thread suggests.

 

I'd say that overall, v36 improved the stumble greatly. I wouldn't say that it cured the stumble completely, but it's rare.