There is provided a method of energising a solenoid of a valve assembly, comprising the steps of applying a positive over boost voltage to the solenoid to actuate a moveable plunger to open or close a flow path through the valve assembly, and then applying a negative braking voltage to brake the movement of the plunger during movement of the moveable plunger. There is also provided a method of energising a solenoid of a valve assembly, the method comprising the steps of receiving a demand signal to actuate the valve, applying a wait time after receipt of the demand signal, applying a positive over boost voltage across the solenoid to actuate a moveable plunger to open or close a flow path through the valve assembly, monitoring the solenoid closure time, and adjusting one or more input variables in order to control the solenoid closure time. There is also provided a method of monitoring the solenoid closure time over a plurality of different energising and de-energising cycles of the solenoid and generating an output to indicate a need for valve maintenance. Finally, there is provided a controller and a valve assembly configured to perform these methods.

An engine including an exhaust bypass valve and an intake bypass valve. The exhaust bypass valve is disposed in an exhaust bypass channel connecting an outlet of an exhaust manifold and an exhaust outlet of a turbocharger to each other. The intake bypass valve is disposed in an intake bypass channel connecting an inlet of an intake manifold and an inlet of the turbocharger. An intake pressure sensor detects a pressure of the intake manifold. If an instruction value indicating an upper limit or a lower limit of the valve opening degree of the intake bypass valve is continuously output for a predetermined time or more, an engine control device determines that an abnormality occurs in at least one of the exhaust bypass valve and the intake bypass valve.

A method for requirement-based servicing of an injector in a common-rail system in which, during ongoing operation of the engine, a current operating point is stored as a function of the rail pressure and of the fuel injection mass, and the current operating point is multiplied by a damage factor and is stored as a reference injection cycle as a function of the rail pressure as well as of the fuel injection mass. A total reference injection cycle is calculated by forming sums over the reference injection cycles, and a load factor is calculated as a function of the total reference injection cycle and the permissible injection cycles, and the load factor is set as decisive for the servicing recommendation of the injector.

Various methods and systems are provided for controlling emissions. In one example, a controller is configured to respond to a sensed exhaust oxygen concentration by changing a fuel injection timing to maintain particulate matter (PM) within a range, and then adjusting an exhaust gas recirculation (EGR) amount based on NOx sensor output and based on the change in fuel injection timing.

A prescribed air-fuel ratio feedback control region for performing feedback-control of air-fuel ratio has therein: a first region where fuel is injected, during one combustion cycle, only from a first fuel injection valve injecting fuel directly into a cylinder; and a second region where fuel is injected, during one combustion cycle, from both of the first fuel injection valve and a second fuel injection valve injecting fuel into an air-intake passage. A second region is configured such that an amount of fuel injected from the first fuel injection valve and an amount of fuel injected from the second fuel injection valve remain at a given constant ratio regardless of operating status. A diagnosis on the first and second fuel injection valves is performed by using a first air-fuel ratio learning value learned in the first region and a second air-fuel ratio learning value learned in the second region.

A method of controlling a fuel injection amount of an internal combustion engine includes a target injection amount calculation step, a component-by-component wear amount estimation step at which a component-by-component wear amount of an injector component is estimated, the injector component being a plurality of members or a part of the member constituting the injector and selected in advance as the injector component affects an accuracy of the fuel injection amount, a component-by-component correction amount calculation step, a total correction amount calculation step, and a total correction amount reflection step at which the injector injects a corrected target injection amount.

An internal combustion engine control device that can ensure diagnosis of whether a fuel injection cut function normally works and that further permits startup of an internal combustion engine in a case in which the fuel injection cut function normally works is provided. To attain the internal combustion engine control system, the startup of the internal combustion engine is prohibited when carrying of a diagnostic monitoring current based on a diagnostic drive signal related to each of fuel injection valves to each of fuel injection valves in a case of transmitting a drive prohibition signal related to each of fuel injection valves to a fuel injection valve drive circuit before the startup of the internal combustion engine and transmitting the diagnostic drive signal related to each of fuel injection valves to the fuel injection valve drive circuit. By transmitting the diagnostic drive signal related to each of the fuel injection valves to the fuel injection valve drive circuit and monitoring whether the diagnostic monitoring current based on the diagnostic drive signal is carried to each of fuel injection valves, it is possible to ensure diagnosis of whether the fuel injection cut function normally works.

A fuel injector system includes an injector body having a proximal end and a distal end, the injector body defining a nozzle having an outlet. The injector system includes a spill valve fluidly connected to the outlet and having a spill valve member movable between an open position and a closed position. The injector system includes a control valve including a control valve member movable between an open position and a closed position. The injector system includes a check valve fluidly connected to the outlet, the control valve including a check valve needle movable between an open position and a closed position. The injector system also includes an electrical monitoring circuit configured to output a signal indicative of at least one of the open position or the closed position of the spill valve member.

Methods and systems are provided for monitoring corking of a valve in a fuel vapor line during diagnostics of the fuel vapor system. In one example, a method may include, upon sealing the fuel vapor system during a diagnostic routine, estimating a threshold pressure of the fuel vapor system based on a fuel level in the fuel tank, and in response to an estimated pressure of the fuel system decreasing to the threshold pressure, opening a canister vent valve coupled to a vent line of the fuel vapor system.

A cold start split injection control method is provided. The method includes a split injection controller which determines cold start conditions of an engine system, an injection mode control which performs a cold start split injection by an operation of an injector and an injection malfunction diagnostic control which performs an injection malfunction diagnostic with any one or more among an injector opening angle, an injector operating time, and the number of injector operation times which are measured through the fuel injection of the injector.