A vehicle includes a pump configured to discharge a fuel by reciprocating a plunger, a rail configured to store the fuel discharged from the pump, and a fuel injection valve configured to inject the fuel supplied from the rail. A controller for the vehicle includes a waveform obtaining unit and a phase shift obtaining unit. The waveform obtaining unit is configured to obtain a waveform of a fuel pressure in the rail as a function of time in a predetermined period. The phase shift obtaining unit is configured to obtain a phase shift based on the waveform obtained by the waveform obtaining unit. The phase shift is an offset between a timing the plunger reciprocated in the pump arrives at a first position and a timing a piston reciprocating in an internal combustion engine arrives at a second position.

Methods and systems for adjusting timing of fuel injectors to reduce cylinder to cylinder air-fuel maldistribution are disclosed. In one example, fuel injection timing is adjusted as a function of pressure ratios that are based on fuel rail pressures observed during injection of fuel. The pressure ratio may be a ratio of a root-mean-square pressure and a scheduling fuel pressure.

Systems and methods are provided for determining and correcting air/fuel imbalance between cylinders of an internal combustion engine. A deactivation strategy is determined and implemented. An evaluation is made of whether the engine is operating with an air/fuel imbalance between cylinders. When an imbalance is identified, an alternate deactivation strategy is implemented. Based on outcomes of the alternate deactivation strategy, a source cylinder of the air/fuel imbalance is identified, and fuel flow to the source cylinder is corrected.

A method and system is provided of controlling a pump having a pumping element configured to provide pressurized fuel to a common rail accumulator coupled to a plurality of fuel injectors configured to inject fuel into a corresponding plurality of cylinders of an engine, comprising: receiving rail pressure values indicating a current fuel pressure in the accumulator; and responding to the received at least one rail pressure value by controlling operation of the pumping element during each potential pumping event of the pumping element to generate actual pumping events during at least some of the potential pumping events to cause the rail pressure values to remain within a desired range and to at least one of increase an overall efficiency of the pump, decrease audible noise generated by the pump, increase reliability of the pump and reduce injection pressure variations at the plurality of fuel injectors.

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 for identifying a continuously injecting combustion chamber of an internal combustion engine which has an injection system with a high-pressure accumulator for a fuel, having the following steps: time-dependent sensing of a high pressure in the injection system; starting a continuous-injection detection process at a starting time while the internal combustion engine is operating; identifying a start time of a pressure drop which occurs chronologically before the starting time and at which the high pressure in the injection system begins to drop if continuous injection has been detected; and identifying at least one combustion chamber to which the continuous injection can be assigned, on the basis of the start time of the pressure drop.

A method for controlling an internal combustion engine, in which, based on a rail pressure signal, a first characteristic variable is specified that indicates a misfire, a misfire being recognized when the rail pressure signal does not have the expected curve.

Methods and systems are disclosed for operating an engine that includes fuel injectors that supply fuel to cylinders of the engine. According to the methods and system, variation of individual fuel injection amounts injected by a sole fuel injector are determined so that it may be determined if individual fuel injector variation may be contributing to engine air-fuel ratio variation.

Methods and systems are provided for injector balancing without disabling a cam actuated high pressure fuel pump. In one example, one of a plurality of cam lobes of the pump is selectively and sequentially disabled while a group of injectors are concurrently operated to learn a pressure drop across each injector. The selection of the injectors is based on the identity and stroke timing of the disabled cam lobe.

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.