Abstract: In an internal combustion engine, a starter motor is energized in response to a request for an engine start to perform a cranking of the internal combustion engine. Thereafter, an electric variable valve motor is energized to control a valve opening/closing characteristic to a condition designed to promote the cranking. The start of the energization of the electric variable valve motor is delayed from the start of the energization of the starter motor at least by a predetermined delay period.

Abstract: In an internal combustion engine, a starter motor is energized in response to a request for an engine start to perform a cranking of the internal combustion engine. Thereafter, an electric variable valve motor is energized to control a valve opening/closing characteristic to a condition designed to promote the cranking. The start of the energization of the electric variable valve motor is delayed from the start of the energization of the starter motor at least by a predetermined delay period.

Abstract: In a hydraulic pressure control system for an engine cylinder cutoff device through which a first group of cylinders are cut off with at least intake valves of engine valves included in the first group kept inactive, while a second group of cylinders are working, the system includes a valve mode switching mechanism being responsive to supply oil pressure for switching an operating mode of at least an intake valve of engine valves of each of the first group of engine cylinders from active to inactive. Also provided is a hydraulic pressure control valve regulating the supply oil pressure. A control unit incorporated in the system sets the supply oil pressure to a predetermined maximum pressure when initiating the inactive mode, and holds the supply oil pressure at a predetermined oil pressure lower than the predetermined maximum pressure before the inactive mode is released.

Abstract: A hydraulic control system for an internal combustion engine is provided which comprises a first hydraulic operating mechanism and a second hydraulic operating mechanism, the first hydraulic operating mechanism and the second hydraulic operating mechanism being operated independently by oil pressure of a common oil press source, and a circulation line that supplies pressure oil discharged from the first hydraulic operating mechanism to the second hydraulic operating mechanism.

Abstract: A hydraulic control system for an internal combustion engine is provided which comprises a first hydraulic operating mechanism and a second hydraulic operating mechanism, the first hydraulic operating mechanism and the second hydraulic operating mechanism being operated independently by oil pressure of a common oil press source, and a circulation line that supplies pressure oil discharged from the first hydraulic operating mechanism to the second hydraulic operating mechanism.

Abstract: In a hydraulic pressure control system for an engine cylinder cutoff device through which a first group of cylinders are cut off with at least intake valves of engine valves included in the first group kept inactive, while a second group of cylinders are working, the system includes a valve mode switching mechanism being responsive to supply oil pressure for switching an operating mode of at least an intake valve of engine valves of each of the first group of engine cylinders from active to inactive. Also provided is a hydraulic pressure control valve regulating the supply oil pressure. A control unit incorporated in the system sets the supply oil pressure to a predetermined maximum pressure when initiating the inactive mode, and holds the supply oil pressure at a predetermined oil pressure lower than the predetermined maximum pressure before the inactive mode is released.