The idle control valve is a canistor the is fixed on the air bonnet tube between the throttle body and the mass air meter, it sticks out from the air tube and one end goes into the air tube with the other end attached to the intake manifold.
You can see it just under the air tube about a foot from the throttle body.
Press on the wire connector clip and pull on the connector at the same time and the clip will slip off, take the icv loose from it's rubber housing,get some q tips and some throttle body spray from parts dealer, spray the carbon out of it and then spray the q tips and clean the rest of the rotary valve thats located on the inside. Shake the residue off, let dry and hook back up. Could very well be the problem your having is from all the vacuum leaks that you car has, get those hoses fixed up.
Hope that helps
Poolman