Somehow I don't have access to the beginner section to respond. The lower left port in the intake of the throttle body feeds the Idle Air Control Valve (the upper left port feeds at least the Fast Idle Thermo Valve and probably the air boost valve). If you block that, and the engine continues to idle well, I suspect your idle screw (at the top of the throttle body) may be backed out too far or the o-ring on it has turned hard and is leaking. Remove the screw, take it to the hardware store and find an o-ring that fits. Reinstall it, then set the base idle.