Hi all,
You guys rock! Helped me a lot to get the cable changed and correctly set up first time. The problem of high idle speeds really was down to a 29 year old cable that wasn't perfect anymore.
Just for those who maybe aren't native speakers, just like me: the "lost idle" bracket you have to look at is the small U-shaped thing on the lower rear of the mechanical levers that transfer the cable's motion to the throttle body. What it does is, it allows the stepper to move the throttle and control the idle speed in a range BEFORE you change the position by depressing the throttle.
This is why it is important to set it up so that the stepper has room to move the throttle.
Two things that might prove helpful:
Check that no carpet or sound deadening blocks the throttle pedal from returning to the zero position, thereby depressing the little switch behind it that tells the ECU you haven't depressed the pedal. Happens so easily....
I wasn't able to reach the point where the cable goes through the bulkead from above. Too many hoses and cables in the way.
It's pretty easy to reach though from below the car. Jack it up on the left hand side, secure with an axle stand and you can reach the cable from behind the CV coupling upwards. Pretty simple even with not so small hands like mine.
Happy Mini everyone!