A controller of a control device of an internal combustion engine includes: a storage configured to store fuel pressure detected during injection of one port injection valve of port injection valves in association with another port injection valve, of the port injection valves, scheduled to inject fuel after one or two cycles of the fuel pressure pulsation elapsing from injection of the one port injection valve; and a calculator configured to calculate an energization period of the another port injection valve based on the stored fuel pressure.

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.

Methods and systems are provided for estimating ethanol content in fuel and an age of the fuel in a vehicle engine. In one example, a method may include estimating fuel ethanol content and/or fuel age based on fuel temperature, a speed of sound in fuel, and an attenuation co-efficient of an ultrasonic signal in fuel. One or more engine operating parameters may be adjusted based on the estimated fuel ethanol content and fuel age.

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.

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.

A fuel pump pressure-feeds fuel to an accumulation container that accumulates high-pressure fuel. A fuel injection valve injects high-pressure fuel accumulated in the accumulation container to an internal combustion engine. A fuel pressure sensor detects a fuel pressure in the accumulation container. A fuel pressure acquisition unit acquires the fuel pressure detected with the fuel pressure sensor. A reference computation unit computes a required injection quantity and an injection start timing based on an operation state of the internal combustion engine at a predetermined reference computation timing, which is set for each combustion cycle of the internal combustion engine, and further to compute an injection time period based on a fuel pressure acquired by the fuel pressure acquisition unit at the reference computation timing. A correction unit corrects the injection time period based on the fuel pressure acquired by the fuel pressure acquisition unit at the injection start timing.

A fuel injection control device includes a reference interval calculation section that calculates a reference interval between an end time of a decrease interval where the pressure decreases as a fuel injection rate increases and a start time of an increase interval where the pressure increases as the fuel injection rate decreases on a pressure waveform detected by the pressure sensor, an integration interval setting section that sets, in the reference interval, an integration interval where an influence of a disturbance on the fuel pressure decrease due to a target injection is suppressible, and a decrease amount calculation section that calculates a corresponding pressure decrease amount, which is a fuel pressure decrease amount corresponding to a maximum injection rate of fuel of the target injection, based on an integral value obtained by integrating the fuel pressure decrease amount due to the target injection in the integration interval.

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.

A method and a device for determining the injection quantity or the injection rate of a fluid which is transported to an injector through a hydraulic line and is injected into a reaction space by the injector. The fluid pressure in the hydraulic line is measured by a pressure sensor, the fluid pressure at the injector is determined using the pressure measured by the pressure sensor and a stored transmission function of the hydraulic line, and the injection quantity or the injection rate of the fluid injected by the injector is determined using the fluid pressure determined at the injector.

The disclosure relates to a control method for controlling at least one injector valve in a fuel injection system of an internal combustion engine. An opening time of the injector valve is selected such that, in a fault situation in the fuel injection system, an opening time of the injector valve is situated in a pressure valley of a pressure oscillation prevailing in a high-pressure region of the fuel injection system.