Holson,
"kabar baik" thankyou. I cannot believe I meet somebody who speaks Indonesian in this site. Anyway I took my car to "PRO motor", and they suggest that I changed the Air flow control valve. But I have a hunch that the trouble is very minor on this car.

Mick J,
Thankyou for replying. How can I find the Idle speed control air valve. How can I clean the Idle valve control? Can I clean it with squirting some carb cleaner into it. I will do this during the week-end since I'm just a DIY-er.