Methods and systems are provided for a phase control apparatus in a variable cam timing (VCT) system of an engine, the phase control apparatus having a locked configuration where a locking pin coupled to a first vane of the vane rotor is engaged with a locking pin recess in a cover plate of the phase control apparatus. In one example, the phase control apparatus includes a rubber or plastic isolator pad positioned in a recess in a wall adjacent to the first vane such that when the vane rotor is rotated to the locked configuration, the first vane contacts the isolator pad before it can strike the housing. The isolator pad serves to maintain the gap between the first vane and the housing, and also reduces the likelihood of other vanes of the vane rotor from striking the housing.

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 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 method according to the invention for controlling an internal combustion engine having a camshaft whose phase with respect to a crankshaft can be adjusted by means of an electric adjustment device, and a control device comprises the steps S1 to S3, wherein in step S1 a stop request is output from the control device to the electric adjustment device. Subsequently, in step S2 a manipulated variable in the form of a pulse duty factor is output from the electric adjustment device, wherein the pulse duty factor counteracts a camshaft torque. In step S3, the direction of rotation of the camshaft is monitored, wherein in step S4, when a reversal of the direction of rotation of the camshaft is detected, an intensity level of this reversal of the direction of rotation is calculated by determining a rotational speed gradient. Furthermore, in a step S5 the pulse duty factor is corrected as a function of the rotational speed gradient in such a way that the influence of the reversal of the direction of rotation on the position of the camshaft is compensated.

In a control device for an engine, the engine includes combustion chambers, ports connected to the combustion chambers, and valves that open and close areas between the combustion chambers and the ports. The control device includes an electronic control unit that is configured to execute an anti-freezing operation of performing control to fully close the valves or make the valves be in a state of being opened with a lift amount of 1 mm or more, in a case where temperatures around the valves are lowered to a predetermined temperature range after the engine is stopped, or in a case where an outside air temperature when the engine is stopped is equal to or lower than a predetermined temperature. The predetermined temperature range is a temperature range in which an upper limit value is lower than 10? C., and the predetermined temperature is lower than 5? C.

A method for starting or stopping an internal combustion engine which reduces starter loading and engine vibrations is provided. The method includes varying a valve stroke of at least one cylinder of the engine such that during the starting or stopping procedure the at least one cylinder undergoes decompression.

A valve open/close timing controller including a driving-side rotating body rotating about a rotating shaft core synchronously with a crankshaft of an internal combustion engine with a driven-side rotating body inside the driving-side rotating body and coaxially with the rotating shaft core that rotates integrally with a camshaft to open/close an intake valve of an internal combustion engine. A phase adjusting mechanism sets a relative rotation phase between the driving-side and driven-side and a phase controller performs a retard operation to shift the relative rotation phase to a most retarded phase by displacing the driven-side rotating body in a direction opposite to the driving-side rotating body, and, when rotational speed of the engine reaches a lower limit rotational speed during stopping of the engine, advances the relative rotation phase as the most retarded phase by displacing the driven-side rotating body in a same direction as the driving-side rotating body.

In a system that selects a large-cam as a driving cam at a time of a start of an engine, when an engine stop request is output, it is determined whether there is a small-cam cylinder for which a small-cam is selected as the driving cam. In a case where it is determined that there is a small-cam cylinder, a switching command for switching the driving cam from the small-cam to the large-cam is output. When an engine start request is output, the above determination is performed again. In a case where it is determined that there is a small-cam cylinder, the switching command is output to all solenoid actuators again. In addition, the drive of the fuel injector is suspended until the switching operation of the driving cam is completed for all cylinders.

Disclosed is a method for determining the state of rotation of a camshaft of a vehicle engine, notable in that the method for determining the state of rotation of the camshaft determines that the state of rotation of the camshaft is in the process of stalling, corresponding to an intermediate state of rotation, when the time elapsed since the last detection of a camshaft wheel tooth-front by the sensor exceeds Tcam_cal, Tcam_cal being defined as the theoretical length of time needed for the camshaft wheel to cover an angular distance equal to the maximum angular distance separating two successive camshaft wheel tooth-fronts at a camshaft rotational speed corresponding to a predetermined low engine speed higher than the minimum engine speed tolerated by the engine.

Methods and systems are provided for controlling an engine system with a variable cam timing device. In one example, the variable cam timing device is operated to adjust engine valve timing differently at engine stop based on whether the engine stop is in response to an operator request or in response to an automatic controller initiated engine stop without an operator request.