I am talking with the BMW about the T-SHAPE IDLE REGULATING VALVE and how it works... finally we think the solution is like follows (I do not know why the BMW do not say nothing of this before
)
Dismounting the valve I can extract a ball that move inside for opening or closing (have a hole through it to air pass) if the hole is greater the idle raise...
The other solutions is send the ECU to the guys Frits said before
but is my second option because is more expensive...
Cheers,
Felix