Idle Speed
 

Hello my friends.
I have tried some other forums and believe me it has been frustrating.
Here i go (again)
my Y2K protege 1.6L 36000Kms runs very good but (but...) when i stop the car (trafic lights) my idle speed turns unstable, fluctuates between 750 and 600RPM and it get worst when my A/C is on (the car starts good cold or hot). I have read in the web this problem could be the idle control valve and that little black box (not so little) can be cleaned. I almost do not resist the temptation. I just know where it is...
My dealer checked the car and the computer interface does not show any fault code, it drives me almost crazy.
Can anyone help me ? any tips ?

Regards
UHZT