US Patent 7853399 Internal combustion engine control apparatus and method

An internal combustion engine control apparatus executes an exhaust-valve-early-closing valve timing control in which an exhaust valve is closed before the intake stroke top dead center. The fuel injection timing mode is normally set to an intake-stroke non-synchronized fuel injection mode. However, if the internal combustion engine is idling and the combustion gas temperature is relatively high, the fuel injection timing mode is switched from the intake-stroke non-synchronized fuel injection mode to an intake-stroke synchronized fuel injection mode.