33.2 did fix my yoyo also, also improved shift response (throttle response in the new gear is slightly quicker - allowing faster shifts without a whole), but stumble is still there. Going back Thursday if possible.

Wes

Wes,

Did they fit the diode you mentioned previously?

I am not sure. I studied the harness and could not tell. The service rep did not answer that question (we played phone tag today). I could not get back in today, but may have time Thursday. I will get more info when I can.
All in all - I do think the car is better, but not 100%. Mine would have been a 33.1 (original with 3/03 build)to 33.2 upgrade - maybe with the diode.

Another installment yet to come.

Wes

Has anyone had a straight answer from Mini about this yoyo hiccup problem? Why does the car exhibit these dangerous and annoying characteristics? Technically speaking WHY? and WHY was the car released like this? What does this diode actually do? I know what A diode does but what does THIS one do in the circuit? Why is it taking one of the most technoligically advanced auto manufacturers years to fix these faults with our cars. And why should we have to pay full price (and more if you really got suckered) to be guinea pig noddy dolls?

I'd be cautious about saying anything is fixed without putting a few hundred miles on the clock. My 3/03 displayed it from the get go but Bluesmaster says his didn't get bad until a few K.

We'll see. and then we'll see.

Mini split the cooling fan power feed (power steering and radiator) once they realized that a bag in he PS fan would pop the fuse and the car would overheat. They made this change (on the fly) by adding/modifing a section of wiring harness (the two film canister looking connectors under the hood just forward and below the ECU in the drivers side (US) headlight well). This "fix" for the fan power feeds had a side affect. The two "split" leads have different size power draws, and can develop different voltage drops. One feeds the Throttle Body apparently. This can result in the TB getting not quite the intended signal or position information. The diode is intended to balance these circuits back out.
This is waht I understood at least from my Service rep. It's all third party and could be in error. I will post some pictures of this connector. and I want some of you to compare with yours.

Wes

Very interesting

Funny if all this yoyoing turned out to be nothing to do with the software and just bad circuit design.

Thanks for the details.

"Funny" as in it would make all the high tech grease monkeys at BMW look like even bigger mongoes than they do now for producing THE YOYO CAR.

I would love to know how they ensured that none of the motoring journos wrote about it. CHIPS or casino CHIPS???

Just logging in my May 7 '03 MCS has the first gear hiccup, only 1 time after starting cold, then it's gone. It does have the 2nd gear 2500-3500ish yo-yo sometimes. The yo-yo sort of comes and goes. Any more news on this diode issue? Software must have something to do with it though since many people did not experience the problem until after a software upgrade.

I have had the diode thing and 33.2 update done, and the car is better in many ways, but I still have the 1st gear hiccup most of the time. Some times I dont get it though, and that is a blessing, because before the fix I always got it. I have not drive much (less than 50 miles) this week since the update, so have not reported much. I will be putting some miles on this weekend and will see.

Wes

What a great website!!! I have had my MCS since Aug. '02 and have tried everything thinking it was my past 3 year absence a straight drive car. I am glad to hear it is not me and it is the car. There is some solace their! However, this sucks! I read one reply that the 15% pulley gets rid of the "start off" lag but here's my question: Does it really? I think it just "masks" the problem and that if it were truly fixed then the pulley would add even more value. I take note of this because I am roughly 2-3 weeks away from getting a pulley installed and want/desire the "full" outpouring of power from standing start to mid-range.

What is everyone's thought? Randy, if you read this, your thoughts? I love this car but, if you are like me, the quest for perfection and tuning is "damn if you do, damn if you don't" and a couple of wins few and far between...??? This is the first car I have ever gotten "performance enhancing" (the car, not me HaHa) addiction! Just have to hope you are making the best decisions. It has been over a year since 1st release and you would hope the "muddy" water was now clear. At least that was what I was waiting for...wishful thinking...I am proceeding on with a careful eye...screw the rest.

I recomend you make all efforts at your dealership to solve the problem before you get the pulley. They will most likely be less responsive after you do that, as they have something to point a finger at then. I agree - the pulley will not get rid of the hiccup, but there will be more torque in that rpm range to "mask" it as you said.

Wes

Originally posted by Wesport
Mini split the cooling fan power feed (power steering and radiator) once they realized that a bag in he PS fan would pop the fuse and the car would overheat. They made this change (on the fly) by adding/modifing a section of wiring harness (the two film canister looking connectors under the hood just forward and below the ECU in the drivers side (US) headlight well). This "fix" for the fan power feeds had a side affect. The two "split" leads have different size power draws, and can develop different voltage drops. One feeds the Throttle Body apparently. This can result in the TB getting not quite the intended signal or position information. The diode is intended to balance these circuits back out.
This is waht I understood at least from my Service rep. It's all third party and could be in error. I will post some pictures of this connector. and I want some of you to compare with yours.

Wes

Wes, Any new update on how the diode fix is working out for you? Could you post a picture as you mention above? I'm hoping 33.3 comes out soon. Sometimes the cutout in first is pretty dramatic and dangerous....
cheers,
Mark

No - this did not salve my problem. I think they have given up on this approach. It was better for one day, but that is just because the ECU was reset. You can get a good day to by disconecting your battery for 15 minutes. You will have less power, but no stumble until it relearns its evil ways (so I have been told - I have not tried this). I understand 34 is our now, but still does not solve the problem. I have given up and bugun mods now. QS exaust, Alta drop in, and Alts rear bar are now on. Pulley soon.

Wes

wes who is the dealer you have been going to in Atlanta?

Global - They have done a good job except for the stumble. I think they are embarresed by the issue, and while they will acknloedge the problem, they don't really want to talk about it much.

Wes

thanks, Im trying to figure out about doing randys pulley/ecu the end of july. i left some posts on MCO.

My dealer updated my Cooper S software to the latest as of July 1st, and the 1st gear stutter and 2nd gear yo-yo are still clearly present. They said they did not understand why it did not fix it, and have collected and sent data to Mini Engineering who advised the tech to stop working on the car and wait for a further fix. Needless to say, I am a very unhappy camper.

Yep I had this problem, my MCS/JCW would set off and then almost die, then start off again! I first noticed whilst pulling out onto a roundabout. At first I put it down to the road being dodgy and TCS kicking in. I spoke to my local dealership, who are pants, and they agreed this was probably the cause. It did a few more times in places there is no possible reason for the TCS to kick in and no audible/visual clues to back up a TCS moment. I spoke to them again and they said it was most probably due to me not having enough revs! After another argument ensued they said it may be to do with the supercharger, which incidentally they had to replace TWICE. In the end they could offer no real explanation for this loss of power. Fortunately for me :D I got a full refund due to this and many other little ‘characteristic’ :rolleyes: niggles.

This was definitely a software issue. I have since had V36 loaded and have had no more of this issue. Still have the yo-yo, but the stumble/bog/stutter are gone.

I'm getting mine (april 2003 MCS) done next Thuesday, I have the stutter, not the yoyo. I really hope it'll help, I'll keep you posted.

Dennis