If an engine coolant temperature is equal to or lower than a first low-temperature determination value and a battery temperature is equal to or lower than a second low-temperature determination value when a request to start up an engine is made, the advancement driving of a variable valve operating mechanism is first started. Then, when an advancement amount of the variable valve operating mechanism later becomes equal to or larger than a prescribed startup start determination value, is started.

An internal combustion engine system includes an internal combustion engine including a cylinder, an intake valve and an exhaust valve, a cylinder injection valve, and a variable valve drive mechanism, and a control device that controls the cylinder injection valve and the variable valve drive mechanism. The control device includes a calculation unit that calculates a first crank angle section where a temperature of the cylinder is equal to or higher than a boiling point of the fuel in a compression stroke before completion of warming-up of the internal combustion engine and a second crank angle section where the temperature of the cylinder is equal to or higher than the boiling point of the fuel in the valve closed period, and an injection controller that executes fuel injection in the first and second crank angle sections by the cylinder injection valve.

If an engine coolant temperature is equal to or lower than a first low-temperature determination value and a battery temperature is equal to or lower than a second low-temperature determination value when a request to start up an engine is made, the advancement driving of a variable valve operating mechanism is first started. Then, when an advancement amount of the variable valve operating mechanism later becomes equal to or larger than a prescribed startup start determination value, is started.

An internal combustion engine system and methods of use are provided. The internal combustion engine system may comprise an engine chamber with a piston, and one or more of the following, configured to enable a negative valve overlap (NVO) mode of operation in which an intake valve opening (IVO) timing is later than an exhaust valve closing (EVC) timing: a continuously variable valve duration (CVVD) mechanism for both an intake valve and an exhaust valve; a dual CVVD and continuously variable valve timing (CVVT) mechanism for both the intake valve and the exhaust valve; and a cam system. The internal combustion system may comprise a fuel delivery system comprising one or more of a direct injector and a port fuel injector; and may comprise an ignition system.

An internal combustion engine system and methods of use are provided. The internal combustion engine system may comprise an engine chamber with a piston, and one or more of the following, configured to enable a negative valve overlap (NVO) mode of operation in which an intake valve opening (IVO) timing is later than an exhaust valve closing (EVC) timing: a continuously variable valve duration (CVVD) mechanism for both an intake valve and an exhaust valve; a dual CVVD and continuously variable valve timing (CVVT) mechanism for both the intake valve and the exhaust valve; and a cam system. The internal combustion system may comprise a fuel delivery system comprising one or more of a direct injector and a port fuel injector; and may comprise an ignition system.