thanks mark, i connect the dashpot thru the brake booster vacuum line by fabricating a T then i connect it to the dashpot. now when i turn the engine the dashpot retracts and when i turn the aircon it extend but not to the point it reaches the throttle linkage. i adjusted it but same result. I decided to just buy a idle up or a valve switch vacuum of a 90s toyota. the problem is it works the other way around when the aircon is OFF there is NO VACUUM making my dashpot extends to the throttle linkage but when i turn ON the aircon there is VACUUM and the dashpot retracts from the throttle linkage. what i need is when aircon is OFF there is VACUUM and when aircon is ON there is NO VACUUM .Is there a way i can use a relay or some sort of electric device that makes my valve switch operate the other way . thanks