The Idle Stabilizer is that little green box that is attached to the driver's
side firewall in the engine compartment and has two round plugs coming from
the bottom of it.  You idle problem may only be that the idle adjustment screw
(that really big slotted screw on your air intake) needs some adjustment.
However in order to adjust the screw you must unhook the Idle Stabilizer and
hook the plugs to each other (bypassing the IS).  Now you can set your idle
and then you hook the IS back up after you are done.
Hope this helps ya.
Ken Wilford
Van-Again
John 3:16