If I disconnect the connector from the EACV valve, idel does not drop and change, does it mean it is a bad EACV or some other parts not sound?

 

The engine should stall out when the plug is unplugged, if not check the valve.

 

What is the idle when the EACV is plugged/unplugged? If it's too high, unplugging it won't drop the idle because something else may be wrong.

And no, the engine should NOT stall when you unplug it. It should idle at the base idle spec for your car, typically around 600rpm or so.

 

The idel is about 900 rpm before I unplug the plug and after I unplug the plug as well.