A characteristic determining device is provided which determines fuel injection characteristics of a plurality of fuel injectors for an internal combustion engine. The characteristic determining device includes a pressure sensor and a plurality of pipes each of which connects between the pressure sensor and one of the fuel injectors. The pressure sensor is designed to have a plurality of pressure inputs from the respective fuel injectors through the pipes and outputs a signal indicative of a level of pressure in each of the fuel injectors. The characteristic determining device analyzes the signals from the first pressure sensor to determine the fuel injection characteristics of the respective fuel injectors. These arrangements result in a simplified structure of the characteristic determining device and a decreased manufacturing cost thereof.

Diagnostic systems and methods for a fuel system of an engine of a vehicle utilize a fuel rail pressure sensor, an engine speed sensor, an exhaust oxygen (O2) sensor, and a controller configured to perform a diagnostic routine for the fuel system during which fuel injectors of the fuel system do not need to be removed from the engine. The diagnostic routine comprises operating the engine at a set of predetermined operating points and detecting one or more malfunctions of one or more of the fuel injectors based on measured fuel rail pressure, measured engine speed, and measured O2 concentration at each of the set of predetermined operating points. Any fuel injector malfunctions detected during the diagnostic routine could be output to a diagnostic device operated by a human technician, e.g., in a single diagnostic report.

Various embodiments of the present disclosure relate to methods and systems for measuring an injected fuel quantity during multipulse injection events in a common rail of a fuel system including a fuel pump to supply fuel to the common rail. The method, using a control unit, determines if each of the multipulse injection events in a normal operating condition includes a pilot pulse; in response to determining that the pilot pulse is included, obtaining an enforced separation value between the pilot pulse and the main pulse to emulate a single-pulse injection; while the fuel pump is temporarily shut off, performing a temporary enforced separation on a fraction of the multipulse injection events; measuring a pressure change in the common rail during the temporary enforced separation; and resuming the normal operating condition of the multipulse injection events after the pressure change is measured.

A method of controlling an engine system includes controlling a fuel injector to perform a zero-fueling injector operation during operation of the engine, the zero-fueling injector operation including a non-zero injector on-time resulting in zero fueling by the injector, determining an injection system pressure change associated with the zero-fueling injector operation, modifying at least one fuel injection control parameter in response to the injection system pressure change, and using the modified fuel injection control parameter to control injection of fuel by the fuel injector during operation of the engine.

Provided are methods and fuel injection systems implemented with a plurality of injectors coupled with a common rail, the common rail coupled with a pressure sensor, and the pressure sensor coupled with a processor. The method includes: identifying, by the processor, one of the injectors to calculate a pressure change rate of the common rail associated therewith; receiving, by the processor, pressure measurements of the common rail from the pressure sensor before and during an injection event within a measurement window; using, by the processor, a pre-injection mean pressure of the common rail to determine a rail pressure drop range that is specific to the identified injector; and calculating, by the processor, the pressure change rate associated with the identified injector based on the pressure measurements of the common rail taken during the rail pressure drop range.

An adaptor for connecting a pressure gauge to a fuel conduit not provided with a connection port. The adaptor may comprise a tube including a schrader valve, threads for engaging the pressure gauge, a standard automotive fuel conduit, and standard automotive connectors connecting the tube to the fuel conduit, and the fuel conduit to a pressurized fuel conduit of a vehicle. The adaptor may be provided as a kit including interchangeable tubes, conduits, and connectors, to accommodate vehicle fuel conduits of different configurations and sizes.

Methods and systems are provided for controlling a fuel system of a vehicle to diagnose whether a fuel filter is functioning as desired. In one example, a method may include, in response to a fuel rail pressure decreasing below a threshold pressure while an engine of the vehicle is running, diagnosing whether degradation of fuel injectors or a fuel pressure regulator of the vehicle has occurred while the engine is not running. Then, only if degradation of the fuel injectors and fuel pressure regulator has not occurred, a fuel filter cleaning routine is performed.

An engine control device controls an engine including a turbo-supercharger, a waste gate valve, an air-bypass valve, and a high-pressure fuel system. The engine control device includes: an air-bypass valve control unit and an abnormality detection unit. The air-bypass valve control unit controls the air-bypass valve. The abnormality detection unit detects an abnormality in the high-pressure fuel system. The air-bypass valve control unit increases an opening degree of the air-bypass valve in accordance with detection of the abnormality by the abnormality detection unit.

The invention relates to a method for testing an electrically activated actuator in a fuel delivery device (10) of an internal combustion engine, wherein the electrical actuator is a controllable valve (15) that is arranged on the inlet side of a high-pressure pump (16). The high-pressure pump (16) conveys fuel into a fuel store (17) having a pressure controller (20). The fuel store (17) is connected to at least one injector (23). The method comprises the following steps: 1) increasing the rotational speed of the high-pressure pump (16), 2) activating the controllable valve (15) until the pressure in the fuel store (17) has reached a first low pressure level, 3) changing the supply of current to the controllable valve (15) by a first specified value such that the controllable valve (15) is opened further and simultaneously maximizing an injection amount by means of the at least one injector (23) until the pressure in the fuel store (17) has reached a first threshold value, 4) activating the controllable valve (15) until the pressure in the fuel store (17) has reached the first low pressure level again, 5) determining a further quantity, which depends on the low pressure level and a maximum value of the pressure that was reached in the fuel store (17).

An apparatus and a method for controlling a flow control valve for a high-pressure fuel pump include: a pressure sensor for fuel in a delivery pipe; a control unit for controlling an operation of a flow control valve by controlling a current applied to a coil; a power switching unit for supplying or blocking driving power supplied to the flow control valve based on a control signal of the control unit; and a current adjustment unit electrically connected/disconnected with the flow control valve by the power switching unit to reduce a current supplied to the flow control valve when the current adjustment unit is connected with the flow control valve. Therefore, a noise and a vibration by collision between the plunger and the core upon closing the flow control valve may be attenuated by adjusting a current amount applied to the coil.