A method for determining a quantity of fuel injected into a cylinder of an internal combustion engine including an injection rail includes: measuring the pressure prevailing in the injection rail during fuel injection from the rail into a cylinder; filtering the pressure measurement; determining the relative minimum and maximum points of the filtered pressure curve; insofar as a first (Pdrop1) pressure drop followed by a pressure rise and then a second (Pdrop2) pressure drop is identified, determining a physical quantity that makes it possible to characterize the first pressure drop and the second pressure drop; and determining the quantity of fuel injected by applying the bulk modulus for the two pressure drops identified as a function of the temperature in the injection rail.

A method for vaporizing fuel is provided. The method comprises heating the fuel in a cylinder of an engine via radiation to vaporize the fuel without ignition. In this way, the fuel may be heated to increase vaporization efficiency prior to ignition.

Methods and systems are provided for increasing a lift pump voltage to a high threshold voltage responsive to a DI pump efficiency being below a threshold efficiency, and increasing a lift pump voltage to a first threshold voltage less than the high threshold voltage responsive to a main jet pump fuel reservoir level being less than a first threshold reservoir level. The approach increases fuel jet pump performance and thereby reducing engine stalls induced by fuel vaporization, while maintaining DI pump efficiency and fuel economy.

A control apparatus for a vehicle may include an engine, a fuel tank, a feed pump, a pressure sensor, a motor and an electric storage apparatus. The feed pump feeds the fuel to a port injection valve. The pressure sensor detects a fuel pressure that is fed to the port injection valve. The motor performs cranking of the engine at start time of the engine. The control apparatus includes an ECU. The ECU controls the feed pump based on a detection value of the pressure sensor and controls the motor in order to start the engine. The ECU controls the feed pump and the motor such that the electric storage apparatus feeds electric power to the motor in preference to the feed pump, when an electric power that the electric storage apparatus is able to output at the start time of the engine is less than a determination threshold.

The present invention relates to a method for operating a fuel supply system for an internal combustion engine, and to a corresponding device. The fuel supply system of an internal combustion engine may include: an outlet of a high-pressure pump coupled to a pressure-limiting valve and a high-pressure fluid accumulator. The method may include, when the internal combustion engine is set into a deactivated state, actuating the high-pressure pump such that, at the outlet side of the high-pressure pump, a pressure is increased such that the pressure-limiting valve is opened.

An ECU acquires a fluid temperature, a coolant temperature and a soak time, and determines whether vapors have been produced in a fuel supply device on the basis of a vapor production prediction map. When the ECU determines that vapors have been produced in the fuel supply device, the ECU reduces a feedback gain. Subsequently, the ECU predicts a vapor production time, and, when the ECU determines that a vapor production end time has been reached, executes normal feedback control.

Methods and systems are provided for increasing a lift pump voltage to a high threshold voltage responsive to a DI pump efficiency being below a threshold efficiency, and increasing a lift pump voltage to a first threshold voltage less than the high threshold voltage responsive to a main jet pump fuel reservoir level being less than a first threshold reservoir level. The approach increases fuel jet pump performance and thereby reducing engine stalls induced by fuel vaporization, while maintaining DI pump efficiency and fuel economy.

Methods and systems are provided for mitigating loss of engine torque due to cavitation in a fuel pump. One example approach is adjusting engine operation or fuel pump operation based on ambient conditions and a measured engine torque being lower than a desired engine torque after a pre-determined duration. The ambient conditions may include one or more of ambient temperature being higher than a temperature threshold, barometric pressure lower than a threshold pressure, and fuel volatility higher than a threshold volatility.

A fuel supply apparatus for an internal combustion engine includes: a feed pump capable of feeding a fuel of the internal combustion engine; a high pressure fuel pump that pressurizes the fuel fed from the feed pump; and a second injector that supplies the pressurized high-pressure fuel to the internal combustion engine selectively. An ECU of the fuel supply apparatus includes: a pulsation width detection unit that detects a pulsation width in a pressure of the fuel fed from the feed pump to the high pressure fuel pump; and a feeding condition determination unit that determines that a condition variation causing fuel vapor to form in the fuel fed to the high pressure fuel pump has occurred when the pulsation width detected by the pulsation width detection unit falls rapidly to a preset threshold variation width.

A cylinder-injection-engine control apparatus includes a fuel injection controller that executes air purge control for performing fuel injection in an intake stroke if fuel pressure is below a predetermined pressure when an engine starts. When executing the air purge control, the fuel injection controller makes a fuel injection time of an injector longer than when the fuel pressure is higher than or equal to the predetermined pressure. When executing the air purge control, if the amount of fuel in a fuel tank is larger than or equal to a predetermined amount and an integrated value of a fuel injection amount (integrated injection amount) since start of the fuel injection is larger than or equal to a predetermined value, the fuel injection controller stops the air purge control.