A fuel injection control apparatus for an internal combustion engine includes a low pressure fuel pump, a low pressure fuel passage, a high pressure fuel pump, a high pressure fuel passage, a fuel injection valve, a high pressure controller, and a low pressure controller. The low pressure controller calculates a feedforward correction amount that increases as a request injection amount of the fuel injection valve increases and an increase rate of the high pressure target value increases when a high pressure target value increases. The low pressure controller calculates a feedback correction amount based on a low-side pressure deviation when the high pressure target value increases. The low pressure controller controls driving of the low pressure fuel pump based on a sum of the feedforward correction amount and the feedback correction amount.

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode includes: a rocker shaft that defines a pressurized oil supply conduit; a rocker arm for receiving the rocker shaft and to rotate around the rocker shaft, the rocker arm including an oil supply passage defined therein; a valve bridge for engaging a first exhaust valve and a second exhaust valve; a first plunger body movable between a first position and a second position, and that in the first position extends rigidly for cooperative engagement with the valve bridge; a check valve disposed on the rocker arm and including an actuator for selectively releasing pressure acting on the first plunger body, the actuator including a needle including a longitudinal disk portion and a disk portion; and an oil discharge circuit for to selectively depressurizing oil under the disk portion of the actuator.

A fuel injection pump includes a plunger, a plunger barrel which supports the plunger, a body which houses the plunger and the plunger barrel, a plate which covers an opening formed on the body, a control lever turnably attached near the plate, and an adjuster bolt which abuts against the control lever to restrict turn of the control lever and is supported by a stay disposed on the plate.

A method and system of periodically cycling an air shutoff valve, upon a pre-determined length of time elapsing since the last valve cycle; or upon the cumulative run time of an engine since the last valve cycle exceeding a pre-determined value.

An engine controller is configured to perform fuel cut-off, which temporarily stops fuel injection, calculate an in-cylinder air amount, which is an amount of air used for combustion in a cylinder, and control an engine based on the in-cylinder air amount. The engine controller includes a residual air amount calculation unit configured to calculate a residual air amount that is an amount of air in the cylinder remaining from a previous cycle during the fuel cut-off so that the residual air amount increases as the number of cycles of intake-exhaust actions in the cylinder increases during the fuel cut-off.

A multi-cylinder engine includes a plurality of cylinders that are fired at uneven intervals. A controller is configured or programmed to overlap a time period that a plunger increases a pressure in a pressurizing chamber and a time period that an electromagnetic valve remains opened in at least the longest one of the intervals at which the firing is conducted in the plurality of cylinders.

A multi-cylinder engine includes a plurality of cylinders that are fired at uneven intervals. A controller is configured or programmed to overlap a time period that a plunger increases a pressure in a pressurizing chamber and a time period that an electromagnetic valve remains opened in at least the longest one of the intervals at which the firing is conducted in the plurality of cylinders.

Disclosed is an exemplary method for optimizing vehicle performance. The method includes determining an optimized drive torque for maximizing vehicle fuel economy and detecting a driver requested drive torque. A determination is made on whether the driver requested drive torque is performance related or safety related. The arbitrated drive torque is set to the optimized drive torque when it is determined that the driver requested drive torque is not performance and safety related. The arbitrated drive torque is set to the driver requested drive torque when it is determined that the driver requested drive torque is either performance or safety related.

A booster pump increases fuel pressure in a high-pressure system of a fuel supply system. A decompression mechanism reduces the fuel pressure. In case of a discharge abnormality of the booster pump which causes rise in the fuel pressure, the fuel pressure control system performs an abnormality handling to cause the decompression mechanism to stop the rise in the fuel pressure. In case of the discharge abnormality, and on determination of a warning-required state, in which the fuel pressure in the high-pressure system possibly exceeds a threshold pressure, a control device causes a warning state, in which the fuel pressure does not exceed the threshold pressure before the rise in the fuel pressure stops, even if the discharge abnormality occurs.

A booster pump increases fuel pressure in a high-pressure system of a fuel supply system. A decompression mechanism reduces the fuel pressure. In case of a discharge abnormality of the booster pump which causes rise in the fuel pressure, the fuel pressure control system performs an abnormality handling to cause the decompression mechanism to stop the rise in the fuel pressure. In case of the discharge abnormality, and on determination of a warning-required state, in which the fuel pressure in the high-pressure system possibly exceeds a threshold pressure, a control device causes a warning state, in which the fuel pressure does not exceed the threshold pressure before the rise in the fuel pressure stops, even if the discharge abnormality occurs.