Intake air control system for internal combustion engine

摘要

An intake air control system for an internal combustion engine having at least one intake valve and a valve operating characteristic varying mechanism which continuously varies a lift amount of the at least one intake valve of the engine. A target intake air flow rate of the engine is calculated along with a command value of the lift amount according to a target engine rotational speed set in an idling condition of the engine and the target intake air flow rate when the engine is determined to be in an idling condition. The valve operating characteristic varying mechanism is controlled according to the calculated lift amount command value.