Boy this tread is getting long! Sorry to see so many of you have a stumble in your cars. My MCS was built in Dec. 02 and it doesn’t seem to have this problem. Have no idea what software version is in the car. I live in Alabama and it gets hot in the summer but the humidity is usually high here. Don’t know if that has anything to do with it not stumbling. My MCS is due for service soon and think I’m telling the dealer not to upgrade the software. Hope MINIUSA develops a fix for everyone yesterday.

Charles

 

"I'm getting increasingly frustrated at the building idea that the MINI has a "mind of its own"


Anyone recall the movie Christine? I think she was recycled and now there is a little bit of her in all of our MINI's!!!

 

>>I'm sorry. This still doesn't do it for me. It sounds good that the car is pre-configured to "learn" the stumble. But let's not forget that NO ONE had the stumble six months ago. Right? This stumble came to any and all of us through a software "upgrade." If it could be brought into the world via software, then it can be taken out just as easily. Or is it that the car "learns" the stumble and then can't "unlearn" it, regardless of the software fix? Is it like a drug addiction? The car has tasted the lovely stumble, but cant give it up....whatever. This is stupid.
>>
>>
I don't believe that a software upgrade caused my MINI to "stumble". They did my first software upgrade after I had the shaking to my MC and when the heat started to hit Phoenix. I know if I park my car in the shade it will run fine until it starts getting a little warm. Too bad the Phoenix is 100 degrees or more for half of the year.

 

>>Does anyone know an information source that would explain what the MINI's specific DME and software programming is trying to do? Perhaps I'm not being very clear, but what I'm looking for is a pretty technical explanation of what exactly is controled via the uploaded software and then where the self-learning algorithms come into play. I wouldn't think that this info would share any trade secrets as it's really just a description of functionality.
>>


http://auto.howstuffworks.com/car-computer.htm

Maybe this will help?

 

Thanks phobol, that helps a lot from a general theoretical perspective...e.g., I now understand what the CAN bus is. What would still be useful is a discussion of the specific system employed by the MINI.

 

There is another very interesting fact acknowledged by the BMW engineers during Phobol's visit there. It appears to be that the stumble or engine stutter tends to become more pronounced when the gas tank is about 1/8 to 1/4 full, and the ambient temperature is above 90F degrees with humidity factor in the 30% to 90% ranges.

While I continue to say that software version update 33.2 has been very clean so far for the Cooper CVT, this week I have experienced the engine stutter (RPM's suddenly dropping while the car is idling in "D" mode from 1,100 RPM to 500 RPM and then bouncing back) meanwhile the gas tank was at or below the 1/4 full mark and the exterior temperature was 95F+ and humidity around 85%.

This problem doesn't happen when the gas tank is full or at least at by the 1/2 mark or either morning or night when both ambient temperature and humidity are lower than in the middle of the day.

To me this is not a problem with the sensors in the car. All the sensors in the car do is to collect data and send it over to the main EMS2000 Siemens DME for further processing. There is definetely a glitch in the software because when the gas tank is low perhaps some sort of vapor lock forms in the tank, the sensors collect this information and add to the mix the high ambient temperature and humidity and bingo! You get a sudden stutter.

I think this is the reason why these problems become so much more evident in warm weather and places with naturally hot climates.

Very interesting findings...stay tuned.

 

It goes against all notions of common sense, but every fuel injected car I've ever owned has performed better with a full tank. You'd think by the time the fuel travelled through the pump and regulators that it's final pressure would be independent of the tank pressure.

 

I think it is a problem with the way the program attempts to interpret all the information is being thrown at. You have a low fuel tank, high heat and humidity, etc, etc, I think the software's algorythim has a hard time trying to detrmine what do do next (Like attempting to shut down the engine or even cutting fuel momentarily) when different environemntal variables come together. I filled up my car last night with gas and I want to see if the same stumble resurfaces when I head out to lunch at the peak of the heat and humidity.

 

Look, just for the record...My car stumbles whether the tank is full, empty, or anywhere in between. My car also stumbles whether the weather (weather the whether?) is hot, cold, mild, rainy, sunny or cloudy. It just stumbles. Okay?

Somebody fix it.

Please.

Ken

 

Ken.......
Your sentiments are right on the money.....and we have been waiting much too long for 'Mini' to communicate directly and honestly with us. I can no longer believe what the service managers tell me......yesterday, I was in to replace my coolant tank and upon questioning, was told directly that a version (not 34.0) has been developed that solves the stumble problem. They keep on assuring me and say they'll let me know when it's available.......yeh, and I'm the real Santa Claus!

 

Same with me, I keep being told that when there is a fix, I will be the first one to be repaired. I would like an update, other than that they are working on it.

 

I may just be bandwagoning here, but I thought that I noticed increasingly nastier stumbles as my tank depleted, and vice versa....immediately after adding Techron, I thought I could feel a difference, but it was possibly just the full-tank phenomenon...

Also, I agree with everyone else...air-conditioning makes my car SUCK. I swear my MC was miles better with the AC on than my MCS is....

 

03 MCS 11/02 build date- no stumble until software installed few months back- just had version 34 installed yesterday- runs a bit "smoother" but stumble still present just as before right at 1900 rpm when accelerating from 1st. Also stumble still present when slowing down in 2nd with foot off gas, when tack hits 1900 rpm car lurches forward with stumble for a sec. nothing about stumble has changed with version 34 yesterday

 

OK my name is Dan and I have a stumble. Wow, I feel much better now.

 

It was a nice cool (65F) night here when I got home from work. I decided to take the long way home. Apart from the MAJOR lurch I got when I engaged 1st gear for the first time, the car ran superbly. No hint of surging, Even power in all gears, the stumble/lurch in first only happened the first time I pulled away. Really made me glad to own the car. Now if it could only run this way all the time.....

Seems that the ambient temp does have something to do with it. For what it's worth I noticed I had about a half a tank of fuel.

 

i have a 9/28/2002 build 2003 mcs without any software upgrades (on purpose, after reading about the software regressions.)

it pulls much, much better under 2000 rpm than the early 2002 mcs demo i tried, but i have NO discernable stumble or hesitation. it just gets up and MOTORS.

the amount of gas in the tank doesn't matter, nor does the temperature, at least up to 86F.

once in a while, i mix in some 100 octane racing gas for an even better jolt......

flyboy 2160

 

As if this particular suggestion hasn't been beaten dead enough, I'm chiming in:

After 2 (nonconsecutive) days of temps over 100 (107 and 105, respectively) I've got to amend my previous opinion that temp. didn't seem to matter: I now wholeheartedly believe that it DOES play a role. Acceleration in these temps has provided me with a surging that I've never noticed before. I mean, sure, I've experienced the somewhat staccato acceleration association with Our Favorite Problem, but this was just a continued pull-fade-pull-fade-pull-fade, etc. This happened with 3/4 tank and 1/2 tank, also respectively.

So, I suppose I'm a better person, as I now understand The Surge.

 

I have an 8/02 build MCS. To deal with the stumble between 1st & 2nd gears, version 33.1 was installed leaving me with with a cold start problem and only a hiccup. Soon after, version 33.2 was installed, eliminating the cold start issue, but not the hiccup. I was in for an oil change, mentioned that the hiccup was still evident and without first telling me, they installed 33.2 a second time.....it seemed to help a bit. I then replaced the stock air filter with a PILO GREEN PERFORMANCE AIR FILTER.........the hiccup was less pronounced and there was noticeable improvement in the smoothness of the engine (my wife even felt it). Now, there is even a soft, pleasant whine to the engine that hadn't been there. This may be the cheapest, short-term way to get some improvement. Now, I find that with just the right engagement between the throttle and the clutch there is no hiccup, but I can't do this every time I pull off. Even though their communication stinks, I think Mini is doing everything they can to recify this for us and all that I have left to do is work on my patience. It's harder for those whose problems are more pronounced and whose driving enjoyment has been most sorely effected.

That's all I have left to say until they get it right. Over and out!

 

I'm back from vacation and am putting more miles on the car after the ECU reflash. I think I have phobol's problem. The stumble returned although not as pronounced as before. I'm now hoping that these engineers he talks about can get this fixed now they know more about our problems.

Graham

 

.....so what about 34.1 that's out now??? I've got an appointment on Wednesday to have a sunroof rattle taken care of and will get this new version installed. Currently on 33.2 (33.1 installed for cold start, created worse cold start, installed 33.2, solved cold start, induced massive stumble).

R

 

Right now we have a lot of confusion (like we didn't before!?). Anyway my car is better than it was but I don't know what they did to it, but it's still not perfect. Neither I nor my dealer knows what version I have though I am pressing them to find out. I'll let you know. I don't think you'd possibly be worse off with 34.1 and that might very well be what I have, again I don't know. The car runs a whole lot better though whatever it is.

Graham

 

OK here's the clincher. Whatever I have right now will not be the basis for my "free" overlay of the pulley software from EvoTech. I had the Evotech software on top or 33.2 but I can't go through this download process but one more tiime. So I need a stumble-free car before I do this overlay.

Graham

 

>>I'm back from vacation and am putting more miles on the car after the ECU reflash. I think I have phobol's problem. The stumble returned although not as pronounced as before. I'm now hoping that these engineers he talks about can get this fixed now they know more about our problems.
>>
>>Graham


Graham,
Glad your back, what is (phobols)
see you Friday
Jan

 

Received an e-mail from someone at BMWNA and he called me back this morning. He heard about the issues I'm having with my MC and he is looking into what can be done for me. I guess the MC's have an un-stable idle issue, but my car has the issue more extreme than others. Sounds like the MC and MCS issues are similar but completely different. He was stating that the MC's sometimes have the issues due to all the unecessary patches that are installed on the MINIs. He is supposed to call me back by tomorrow. Hopefully this will all get worked out and maybe get a rental car until I'm comfortable driving my MINI. :smile:

 

I had a problem with my MINI-S being hard to start when it was cold. The problem was getting progressively worse so I took the car to CREVIER in Santa Ana, CA. They determined that it was a software problem and they re-flashed the ECU. After I left the dealer I noticed the "stumble" for the first time. It was consistent at any temp and at any acceleration rate. The dealer could not isolate the problem so they called BMW. BMW asked that the ECU be removed from the car and sent to them for evaluation, since this problem had not been solved and may other complaints had been logged. BMW had the ECU for almost two weeks. Fortunately, the dealer loaned me a 325i (5 speed) for the duration. They got the ECU back from BMW and noticed that the problem was actually worse than before. It was finally decided that a new ECU should be installed. That seemed to solve the problem. The only thing I have noticed is a split-second delay in the throttle response. I will bring that up at my 10K oil change, which will be in amout 1200 miles. My point is, the "stumble" seems to be electronic, not mechanical...