A method and system is provided for correcting fueling commands. For example, the method and system may calibrate an engine operating in a steady-state mode by determining a plurality of accuracy errors associated with a fueling rate based on a plurality of sensor measurements. The method and system may determine fueling rate correction data during on-line operation of the engine based on the plurality of accuracy errors. The on-line operation of the engine may comprise operating the engine in a transient mode at a first period of time and a steady-state mode at a second period of time. The method and system may control at least one fueling valve during operation of the engine using a corrected fueling command. The corrected fueling command is based on the fueling rate correction data.

Methods and systems are provided for vehicle direct injection fuel pump control. In one example, a method may include reducing a flow speed of fuel from a cam-driven direct injection fuel pump for at least half of a total duration of an output stroke of the fuel pump. A cam driving the fuel pump may reduce the flow speed at a first rate during a main portion of the output stroke, and the cam may reduce the flow speed at a second rate during an end ramp portion of the output stroke.

Disclosed is a method of alerting to the state of a high-pressure pump of an engine including a relief valve, a threshold pressure defining the opening pressure of the relief valve, the pump supplying fuel under pressure to a chamber equipped with a pressure sensor, including the following steps: initializing a computer when the engine is cut off during which cut-off a threshold pressure and a value of a first counter are collected in a memory associated with the computer; measuring the pressure of the fuel in the chamber; incrementing the first counter if the pressure of the fuel in the chamber is above or equal to the threshold pressure; and triggering an alert when the value of the first counter crosses a predetermined threshold.

Methods and systems are provided for vehicle direct injection fuel pump control. In one example, a method may include reducing a flow speed of fuel from a cam-driven direct injection fuel pump for at least half of a total duration of an output stroke of the fuel pump. A cam driving the fuel pump may reduce the flow speed at a first rate during a main portion of the output stroke, and the cam may reduce the flow speed at a second rate during an end ramp portion of the output stroke.

A control device for controlling an engine provided with a fuel pump including a pressurizing chamber, a plunger inserted into the pressurizing chamber and which changes a volume of the pressurizing chamber, and an on-off valve configured to open and close a suction port, is provided. When a pressurizing cycle consists of a period of pressurizing stroke in which the volume of the pressurizing chamber is reduced to allow fuel to be pressurized and a period of suction stroke in which the volume of the pressurizing chamber is increased to allow fuel to be drawn into the pressurizing chamber, a closing cycle of the on-off valve is controlled so that a ratio of the closing cycle to the pressurizing cycle becomes smaller in a second combustion mode where a partial compression-ignition combustion is performed than in a first combustion mode where SI combustion is performed.

A method and system is provided for correcting fueling commands. For example, the method and system may calibrate an engine operating in a steady-state mode by determining a plurality of accuracy errors associated with a fueling rate based on a plurality of sensor measurements. The method and system may determine fueling rate correction data during on-line operation of the engine based on the plurality of accuracy errors. The on-line operation of the engine may comprise operating the engine in a transient mode at a first period of time and a steady-state mode at a second period of time. The method and system may control at least one fueling valve during operation of the engine using a corrected fueling command. The corrected fueling command is based on the fueling rate correction data.

A control device for controlling an engine provided with a fuel pump including a pressurizing chamber, a plunger inserted into the pressurizing chamber and which changes a volume of the pressurizing chamber, and an on-off valve configured to open and close a suction port, is provided. When a pressurizing cycle consists of a period of pressurizing stroke in which the volume of the pressurizing chamber is reduced to allow fuel to be pressurized and a period of suction stroke in which the volume of the pressurizing chamber is increased to allow fuel to be drawn into the pressurizing chamber, a closing cycle of the on-off valve is controlled so that a ratio of the closing cycle to the pressurizing cycle becomes smaller in a second combustion mode where a partial compression-ignition combustion is performed than in a first combustion mode where SI combustion is performed.

Disclosed is a method of alerting to the state of a high-pressure pump of an engine including a relief valve, a threshold pressure defining the opening pressure of the relief valve, the pump supplying fuel under pressure to a chamber equipped with a pressure sensor, including the following steps: initializing a computer when the engine is cut off during which cut-off a threshold pressure and a value of a first counter are collected in a memory associated with the computer; measuring the pressure of the fuel in the chamber; incrementing the first counter if the pressure of the fuel in the chamber is above or equal to the threshold pressure; and triggering an alert when the value of the first counter crosses a predetermined threshold.

Provided is a method for diagnosing unintended fuelling from one or more fuel injectors of a multi cylinder internal combustion engine during engine operation. Pressurized fuel is intended to be distributed by means of said fuel injectors from said accumulator tank to the cylinders for combustion. An oxidation catalyst is arranged downstream said cylinders. The method comprises: determining the pressure in the fuel accumulator tank and whether said pressure is decreasing; and determining whether the actual amount of fuel provided by the pump unit exceeds the demanded amount of fuel. The method further comprises the steps of: determining whether the temperature associated with the oxidation catalyst is above a certain level and/or determining whether the air/fuel ratio is below a certain level and/or determining whether an amount of particulate matter is above a certain level; and confirming an unintended fuelling based on the determined conditions.

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.