Within the recent week my car has begun to stumble when revved at start-up, one time it even stalled. This is a new problem within the last week and I have no idea what could have caused it to start happening all of a sudden. The car is a 2005 MCS with 8600 miles on it. Has anyone else experienced this problem, any thoughts on what it could be? Thanks
Happy motoring!

Sincerely,

Kevin M.

 

yes! i was just about to post this. i have 05 S with 7k miles on it. i have the EXACT same problem as you. upon cold start up, i give it a little gas and it almost sounds as if it were going to stall. it only happens on cold startup. also it has been raining a lot this past few weeks.

after driving it around a bit and the engine has warmed up, this problem goes away. if i were to shut the car off when it is warm and try starting again, there are no problems. any ideas? could it be a SW issue?

 

I get that every now and then on my 04 (May build date). It only seems to happen when the car is cold and the temp outside is fairly warm (70-ish). It doesn't happen all the time so it doesn't concern me overly much.


Oh, and none of the mods I've done to my car have anything to do with the ignition system (short of the stereo but I've got a heavy duty capacitor hooked up) so I don't think that has anything to do with it.

 

My MINI dealer advised me to try 89 octane gas instead of 92 or higher and it helps.

 

sweet, cheaper gas! save some money....

 

I have an 05 MCS with just over 8K miles on it and I also have this issue. Seems to idle a bit rough until it warms up. Kind of pulses, if that makes sense. This is really interesting.

 

On my 03, the motor sputters when backing out of my garage on warm humid days unless I:

Place key in ignition, turn to "ON" position, wait 5 sec.
DSC light gots off
Start car.

No issues ever since.

 

I called Mini of Peabody and talked to service. They said it was because of the switch over to summer gas. He said most cars dont seem to have a problem with it but the Mini for some reason has some trouble. I have an oil change soon and I am thinking of having them reset the ECU so that the car thinks its the only gas is ever run on.

 

Summer gas???

 

That's what I was going to say. We had our first stumble this weekend too on my 2005 with 7K. I guess I could accept that it had to do with some change in the weather, but what do they do to the gas as the weather warms up???

 

Did he say that with a straight face?

Hum! The MINI engine stumbles because it is suffering from alcohol withdrawal now we no longer feed it winter gas.

My 05 MCS also recently developed this problem. It never happen before but all of a sudden around 5000 mile. It only occur in the morning when I start it the first time. All of these episodes occured in mornings not too cold. The engine will drop RPM so long that the engine nearly stalls but most of the time did not. Within about 20-30 seconds the idle RPM then increase to normal and the car runs fine after. Of about 15 times now this occured only about twice it actually stalled and requires a restart. The restart always worked.

Seems more like a corner case with the cold start management.

 

There are a number of threads on this right now,they should be merged.

As I posted on another today, It seems to be 100% software related. I have not had it happen once since flashing to MTH last week. It would happen to me almost every morning, stock.

 

Yes, in metropolitan areas including Chicago we use summer gas and
winter gas. Winter gas is oxygenated so it burns easier...people tend
to idle their cars during cold startups which is a problem for emmissions
while using regular (summer) gas.



Oct - April is winter gas season.

 

I've had the same problem with my modded 04 MCS during the last few weeks, not every morning, but 2-3 times a week. I wouldn't recommend using 89 octane. The "cheaper" fuel question continues to come up in almost every thread these days. Yes the MINI will run on 89, heck it will probably run on the cheapest gas out there, but-and this is a BIG but-do you want to rely on the knock sensor to function(especially on the S)to keep from burning nice little holes in the tops of your pistons? I'd burn 93 if I could find it.


2004 MCS EB/EB, sport pkg, lapis leather, 15% pulley, Alta intake, densos, Milltec exhaust.

 

Well... I didnt feel like waiting for the dealer to attend to this so I took it upon myself and reset the ECU. After this the car started up perfectly, and I revved it a good amount to get the ECU trained, shut it off then drove the **** out of the car. I think this will solve the problem, if not off to the dealer it is!
Thanks for the posts,

Sincerely

Kevin M.

 

Did you just disconnect the battery?

 

No, I did it through the speedometer, very simple...

 

I can't seem to get that to work for me. I can't figure out what the display is showing me. Could you post the directions that work for you?

 

car started up just fine this morning, without any stumble. weather was dry and warm as opposed to wet and cold the other day. same tank of gas, same incline of floor, same time of day just different weather conditions. i didnt do any battery reset or fiddling of any kind. this leads me to believe its the weather causing this.

i had a 2000 jetta before that had a bad coil pack. any time it was wet outside it would misfire on my cylinders causing stumbles...

 

I was successful at doing a software reset using the instructions below, but it didn't solve the stumble problem for me.

See the insturctions posted by C4 on this thread.