good day to all the members, I am newbie here, may I know what is the cause of my cars idle dropping when the aircon engage? at idle with no AC, rpm is at 750, when I turn on the AC, it would drop to 450 to 500 rpm that causes the engine to shake and it return immediately to 750 rpm. I am thinking of the FICD or AAC valve that is not working. Please help, its uncomfortable if engine is shaking everytime the aircon engage to on. thanks