Systems and methods are provided for diagnosing cylinders. In one example, a system includes an engine having a plurality of cylinders coupled to a crankshaft, a crankshaft speed sensor, and a controller. The controller is configured to receive a first output from the crankshaft speed sensor during nominal engine operation, receive a second output from the crankshaft speed sensor during engine operation where a fueling disturbance is introduced to a cylinder of the plurality of cylinders, indicate that the cylinder is unhealthy responsive to a difference between the first output and the second output being less than a threshold difference, and adjust one or more operating parameters of the engine in response to the indication.

Systems and methods are provided for diagnosing cylinders. In one example, a system includes an engine having a plurality of cylinders coupled to a crankshaft, a crankshaft speed sensor, and a controller. The controller is configured to receive a first output from the crankshaft speed sensor during nominal engine operation, receive a second output from the crankshaft speed sensor during engine operation where a fueling disturbance is introduced to a cylinder of the plurality of cylinders, indicate that the cylinder is unhealthy responsive to a difference between the first output and the second output being less than a threshold difference, and adjust one or more operating parameters of the engine in response to the indication.

A method for stopping an engine within a desired crankshaft angular range is disclosed. In one example, the method may take no control actions if it is determined that the engine will stop within the desired crankshaft angular range. However, if it is determined that the engine may stop outside of the desired crankshaft angular range, expansion combustion may be initiated in a cylinder so that the engine stops in a desired crankshaft angular range.

A method for stopping an engine within a desired crankshaft angular range is disclosed. In one example, the method may take no control actions if it is determined that the engine will stop within the desired crankshaft angular range. However, if it is determined that the engine may stop outside of the desired crankshaft angular range, expansion combustion may be initiated in a cylinder so that the engine stops in a desired crankshaft angular range.

A high-pressure injection device for an internal combustion engine to which engine segment times are assigned, having a high-pressure pump, a rail connected to the high-pressure pump via a high-pressure fuel line, at least one injector, a digital pressure reduction valve connected to the rail, a fuel return line connected to the pressure reduction valve, and a control unit. The control unit is configured to switch the pressure reduction valve into the transmissive state only in predetermined engine segment times, and to maintain said transmissive state of the pressure reduction valve for a time period which is greater than the duration of one engine segment time.

A method for detecting continuous injection during the operation of an internal combustion engine with an injection system having a high-pressure accumulator for a fuel, wherein —a high pressure in the injection system is monitored as a function of time, wherein —in order to detect continuous injection it is checked whether the high pressure has dropped by a predetermined continuous injection differential pressure value within a predetermined continuous injection time interval, wherein —it is checked whether a reduction valve which connects the high-pressure accumulator to a fuel reservoir has been triggered, and wherein —continuous injection is detected if —a reduction valve has not been triggered in a predetermined checking time interval before the dropping of the high pressure, and if —the high pressure has dropped by the predetermined continuous injection differential value amount within the predetermined continuous injection time interval.

The present invention determines whether multi-stage injection control is operating normally or abnormally, and carries out a failsafe of multi-stage injection control as necessary. The present invention, which solves the problem described above, has means such as the following. The invention is provided with fuel injection valves provided respectively to each cylinder, an opened/closed valve detection means for detecting either one or both of an open valve state and a closed valve state of the fuel injection valves on the basis of the drive currents or drive voltages of the fuel injection valves, and a detection execution determination means for determining a detection execution time period including the detection start timing and the detection end timing of the open valve state or closed valve state; detection interference such as overlapping detection with another cylinder and overlapping of open valve detection and closed valve detection being preventable, and risks such as erroneous detection being reducible.

A direct-injection, supercharged internal combustion engine having at least one cylinder, in which each cylinder is equipped with a direct injection apparatus, a fuel supply system comprising a high-pressure side and a low-pressure side, and a high-pressure piston pump comprising a piston displaceable in translational fashion between a bottom dead center and a top dead center of a pressure chamber of variable volume. The displaceable piston jointly delimits the pressure chamber with variable volume in such a way that a displacement of the piston causes a change in the volume of the pressure chamber via actuation of least one movable actuation element.

A fuel supply device for a liquefied petroleum direct injection (LPDI) engine in which liquefied petroleum gas (LPG) is directly injected into a combustion chamber and a start control method of an LPDI engine having the fuel supply device, wherein the high pressure fuel pump receives and compresses fuel to a pressure higher than a pressure at which fuel has been supplied, wherein the high pressure fuel rail buffers and supplies fuel to a direct injector that injects fuel directly into a combustion chamber, wherein the return line is connected to the supply line through the high pressure fuel pump to form a low pressure line, allowing a surplus portion of fuel supplied to the high pressure fuel pump from the fuel tank to return to the fuel tank, and wherein a first valve is disposed on the return line to control the flow rate of returning fuel.

The present invention describes a fuel-management system for minimizing particulate emissions in turbocharged direct injection gasoline engines. The system optimizes the use of port fuel injection (PFI) in combination with direct injection (DI), particularly in cold start and other transient conditions. In the present invention, the use of these control systems together with other control systems for increasing the effectiveness of port fuel injector use and for reducing particulate emissions from turbocharged direct injection engines is described. Particular attention is given to reducing particulate emissions that occur during cold start and transient conditions since a substantial fraction of the particulate emissions during a drive cycle occur at these times. Further optimization of the fuel management system for these conditions is important for reducing drive cycle emissions.