Abstract: Methods and systems are provided for estimating ethanol content in fuel, water content in fuel, and an age of the fuel in a vehicle engine. In one example, a method may include estimating fuel ethanol content, water content, or fuel age based on a resonant frequency (f) of pressure pulsations, a change in fuel rail pressure (?p), and a damping coefficient (?) of pressure pulsations in the fuel rail as estimated after a fuel injection or a pump stroke. One or more engine operating parameters may be adjusted based on the estimated fuel ethanol content, water content, and fuel age.

Abstract: Methods and systems are provided for a fuel injector. In one example, a system comprises an injector spool valve having a fuel outlet shaped to flow fuel to different portions of a nozzle inlet based on an actuation of the injector spool valve, thereby adjusting a fuel injection angle of a fuel injection.

Abstract: Methods and systems are provided for estimating ethanol content in fuel, water content in fuel, and an age of the fuel in a vehicle engine. In one example, a method may include estimating fuel ethanol content, water content, or fuel age based on a resonant frequency (f) of pressure pulsations, a change in fuel rail pressure (?p), and a damping coefficient (?) of pressure pulsations in the fuel rail as estimated after a fuel injection or a pump stroke. One or more engine operating parameters may be adjusted based on the estimated fuel ethanol content, water content, and fuel age.

Abstract: Methods and systems are provided for estimating ethanol content in fuel, water content in fuel, and an age of the fuel in a vehicle engine. In one example, a method may include estimating fuel ethanol content, water content, or fuel age based on fuel rail temperature, and two or more of a resonant frequency (f) of pressure pulsations, a change in fuel rail pressure (?p), and a damping coefficient (?) of pressure pulsations in the fuel rail as estimated after a fuel injection or a pump stroke. One or more engine operating parameters may be adjusted based on the estimated fuel ethanol content, water content, and fuel age.

Abstract: Methods and systems are provided for operating a high pressure injection pump to provide each of high fixed fuel pressure at a port injection fuel rail and high variable fuel pressure at a direct injection fuel rail. Port injection fuel rail pressure can be raised above a pressure provided with a lift pump via a fuel system configuration that includes various check valves, pressure relief valves, and a spill valve positioned between an inlet of the high pressure injection pump and the port injection fuel rail. High pressure port injection may be advantageously used to provide fuel at high pressure during conditions when fuel delivery via high pressure direct injection is limited.

Abstract: Methods and systems are provided for an injector. In one example, the injector comprises at least two passages, wherein outlets of each of the passages are differently shaped than corresponding inlets of the passages.

Abstract: Methods and systems are provided for a fuel injector. In one example, a system may include an injector comprising two or more passages shaped to flow a mixture in opposite directions before injecting the mixture.

Abstract: Methods and systems are provided for a fuel injector. In one example, a system may include an injection nozzle having a venturi shape with an upstream twisted fin arranged in a venturi inlet. The system may further include a downstream twisted fin arranged in a venturi outlet.

Abstract: Methods and systems are provided for a multi-hole nozzle of a fuel injector. In one example, a nozzle for a fuel injector may include multiple nozzle holes arranged at a nozzle tip, where each nozzle hole has a straight flow axis and a cross-section that twists around the straight flow axis, from an inlet to an outlet of the nozzle hole. Additionally, a long side of the cross-section may increase in length, along the nozzle hole, from the inlet to the outlet.

Abstract: A fuel injector and method are disclosed including an injector body with a fuel sac, and an end positioned into a combustion chamber. A main fuel passage, having a varying cross-sectional area forming a reduced pressure region, fluidically couples the fuel sac to the combustion chamber. One or more additional passages fluidically couple the reduced pressure region with one or both of the fuel sac and the combustion chamber.

Abstract: Methods and systems are provided for a fuel injector. In one example, a system may include forming an annular venturi passage between an outlet surface of the fuel injector and a nozzle. The nozzle may further comprise one or more air entraining features that may work in concert with the annular venturi passage to promote air-fuel mixing.

Abstract: Methods and systems are provided for reducing direct injector fueling errors due to injection variability in a transition region of a direct injector map. Fuel injection, including usage of one or more direct and port injected fuel pulses, may be planned based on engine operating conditions including engine temperature and driver demand. Responsive to any of the direct injected fuel pulses having a pulse-width that lies in a high variability transition region of the direct injector, the fuel injection may be adjusted via adjustments to a number and/or split ratio of the injections so as to not operate in the transition region.

Abstract: Methods and systems are provided for a fuel injector. In one example, a system may include forming an annular venturi passage between an outlet surface of the fuel injector and a nozzle. The nozzle may further comprise one or more air entraining features that may work in concert with the annular venturi passage to promote air-fuel mixing.

Abstract: A fuel injector and method are disclosed including an injector body with a fuel sac, and an end positioned into a combustion chamber. A main fuel passage, having a varying cross-sectional area forming a reduced pressure region, fluidically couples the fuel sac to the combustion chamber. One or more additional passages fluidically couple the reduced pressure region with one or both of the fuel sac and the combustion chamber.

Abstract: Methods and systems are providing for improving zero flow lubrication (ZFL) of a high pressure fuel pump coupled to direct fuel injectors via a direct injection fuel rail. A ZFL transfer function for the fuel pump is learned while fuel is at non-nominal fuel bulk modulus conditions and corrected for variations from a nominal fuel bulk modulus estimate. When zero flow lubrication of the pump is requested, the pump is operated with a duty cycle based on the learned transfer function and an instantaneous estimate of the fuel bulk modulus to compensate for differences in fuel condition from the nominal fuel bulk modulus estimate.

Abstract: Methods and systems are provided for reducing direct injector fueling errors due to injection variability in a transition region of a direct injector map. Fuel injection, including usage of one or more direct and port injected fuel pulses, may be planned based on engine operating conditions including engine temperature and driver demand. Responsive to any of the direct injected fuel pulses having a pulse-width that lies in a high variability transition region of the direct injector, the fuel injection may be adjusted via adjustments to a number and/or split ratio of the injections so as to not operate in the transition region.

Abstract: Methods and systems are provided for pressurizing a step chamber of a direct injection fuel pump. In one example, the step chamber may be pressurized to a pressure higher than an output pressure of a lift pump, the lift pump supplying fuel to the direct injection fuel pump. The pressurization of the step chamber may occur during at least a portion of a pump stroke of the direct injection fuel pump.

Abstract: Methods are provided for controlling a solenoid spill valve of a direct injection fuel pump, wherein the solenoid spill valve is energized and de-energized according to certain conditions. A control strategy is needed to operate the direct injection fuel pump when small fractional trapping volumes are commanded, wherein a small amount of fuel is compressed and sent to the direct injection fuel rail. To maintain reliable and repeatable solenoid spill valve behavior for small fractional trapping volumes, methods are proposed that involve energizing the solenoid spill valve for a minimum angular duration below a trapping volume fraction threshold.

Abstract: Methods and systems are provided for operating a high pressure injection pump to provide each of high fixed fuel pressure at a port injection fuel rail and high variable fuel pressure at a direct injection fuel rail. Port injection fuel rail pressure can be raised above a pressure provided with a lift pump via a fuel system configuration that includes various check valves, pressure relief valves, and a spill valve positioned between an inlet of the high pressure injection pump and the port injection fuel rail. High pressure port injection may be advantageously used to provide fuel at high pressure during conditions when fuel delivery via high pressure direct injection is limited.

Abstract: Methods and systems are provided for delivering fuel to a port injector fuel rail in a port fuel direct injection (PFDI) engine. In one example, the port injector fuel rail may receive fuel from each of a compression chamber and a step chamber of a direct injection fuel pump coupled in the PFDI engine. In this way, pressurized fuel may be supplied to the port injector fuel rail during an entire cycle of the direct injection fuel pump.