A slider control module, based on a mode command: selectively extends pins into one or more slider actuators of a camshaft slider. Contact between the pins and the grooves in the slider actuator(s) during rotation of a camshaft slides the camshaft slider axially along the intake camshaft. An actual mode module: determines a last stored indicator of the mode command; commands the slider control module to extend one of the pins to slide the camshaft slider and achieve the last stored indicator of the mode command; and, based on whether the one of the pins extended in response to the command, indicates that an actual mode is either: (i) the last stored indicator of the mode command; or (ii) another mode. The mode command module updates the mode command to the actual mode.

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine comes to a complete stop, an intermittent engine restart is initiated.

A disclosed method of automatically stopping and restarting a vehicle engine determines if one or more stop/start enablement condition has been met. If the stop/start enablement condition or conditions have been met, the method initiates an engine shutdown. If a restart request is made before the engine comes to a complete stop, an intermittent engine restart is initiated.

An engine control system for a vehicle includes a shutdown control module that generates a command to shut down an engine of the vehicle when at least one of: a driver requests the shutdown of the engine via an ignition system; and when one or more predetermined conditions are satisfied for shutting down the engine without the driver requesting shutdown of the engine via the ignition system. A valve control module, when the command to shut down the engine is generated, advances an exhaust camshaft phaser based on a predetermined exhaust park position. When the exhaust camshaft phaser is in the predetermined exhaust park position, an exhaust valve of a cylinder is fully closed during an exhaust stroke of the cylinder before a piston of the cylinder reaches a topmost position for a next intake stroke of the cylinder.

A lock determination device for variable valve timing mechanism includes means for detecting an operating position of a variable valve timing mechanism having a function of locking a valve timing of an internal combustion engine in an intermediate position between a most retarded position where the valve timing is most retarded and a most advanced position where the valve timing is most advanced in stopping operation of the internal combustion engine, means for starting a timer when the operating position of the variable valve timing mechanism enters an intermediate region, the intermediate region being a predetermined region including the intermediate position, means for determining whether or not the operating position of the variable valve timing mechanism is in a determination holding region wider on a retardation side than the intermediate region after the timer is started, means for incrementing a value of the timer if the operating position of the variable valve timing mechanism is in the determination holding region, and means for determining that the operating position of the variable valve timing mechanism has been locked in the intermediate position when the value of the timer reaches a predetermined value.

A control system for an internal combustion engine is provided with a crankshaft, an intake camshaft with an intake cam, a timing chain, an intake variable valve timing mechanism configured to be able to change at least one of an opening timing and closing timing of an intake valve by controlling a phase of the intake cam, and an electronic control unit configured to set in advance a periodic correction coefficient to vibrate by a period identical to a rotational period of the timing chain and to control the intake variable valve timing mechanism by the periodic correction coefficient to make the phase of the intake cam a target phase.

A system according to the principles of the present disclosure includes a switching period module and at least one of a valve lift control module and a start-stop control module. The switching period module determines a switching period that elapses as a valve lift actuator of an engine switches between a first valve lift position and a second valve lift position that is different than the first lift position. The switching period begins when a measured position of the valve lift actuator corresponds to the first lift position and the switching period ends when the measured position of the valve lift actuator corresponds to the second lift position. The valve lift control module controls the valve lift actuator based on the switching period. The start-stop control module determines whether to automatically stop the engine based on the switching period.

Various systems and methods are described for controlling fuel injection in a variable displacement engine. One method for a deactivatable cylinder comprises, before deactivating the cylinder responsive to operating conditions, disabling a port injector and fueling the cylinder only via the direct injector. The method further comprises, when reactivating the cylinder from deactivation, enabling both the port injector and the direct injector, and injecting a higher amount of fuel via the direct injector while simultaneously injecting a lower amount of fuel via the port injector.

Methods and systems are described for an engine with a cam torque actuated variable cam timing phaser. Phaser positioning control is improved by reducing inaccuracies resulting from inadvertent spool valve and/or phaser movement when the spool valve is commanded between regions. In addition, improved spool valve mapping is used to render phaser commands more consistent and robust.

A decompression device for an internal combustion engine comprises a valve rocker shaft bracket and a valve rod. A valve spring is sleeved on the valve rod, and above the valve rod a valve rocker is arranged. The valve rocker shaft bracket is connected to a decompression bracket. The valve rocker is movably connected to a valve opening/closing device connected with a control device. When the internal combustion engine is started, the valve opening/closing device receives a control command from the control device to keep connecting with the valve rocker for a time, and then disconnect, so that the valve rod arrives at the valve closing position.