A control method dedicated to the management of an injector of an internal combustion engine, the internal combustion engine being coupled to a device for the post-treatment of the exhaust gases, when an additional injection for treating the gases or an additional injection for calibrating the injection is demanded by the controller, the method including a step of combining the gas-treatment additional injection and the additional injection for calibrating the injection into one, the combining-into-one being performed when additional-injection parameters are compatible.

Methods and systems are provided for learning fuel injector error for cylinder groups during a deceleration fuel shut-off (DFSO), where all cylinders of an engine are deactivated, sequentially firing each cylinder of a cylinder group, each cylinder fueled via consecutive first and second fuel pulses of differing fuel pulse width from an injector. Based on a lambda deviation between the first and second pulses, a fuel error for the injector and an air-fuel ratio imbalance for each cylinder is learned. Alternatively or additionally, a difference in crankshaft acceleration between the first and second pulses relative to the expected deviation may be used to learn torque error, and adjust fuel injector error and air-ratio imbalance for each cylinder.

The invention relates to a method for determining the injection rate of an injection valve (1) using a mathematical model which is based on measurement values comprising the stroke (x) of a piston (3) that delimits a measurement chamber (2) during the injection of a test fluid (4) into the measurement chamber (2). The injection rate is corrected on the basis of an additional measurement value. According to the invention, the pressure (p.sub.a) in an adapter volume (5), via which the injection valve (1) is connected to the measurement chamber (2), is used as an additional measurement value for correcting the injection rate. The invention further relates to a device for determining the injection rate of an injection valve.

There are described methods and systems for testing operation of a solenoid valve in a control system. A valve command is sent to successively open and close a solenoid valve. A flow command from a control system is monitored to detect a change in the flow command in response to the valve command. The flow command is associated with regulation of fluid flow in a process controlled by the control system. Operation of the solenoid valve is confirmed when the change in flow command is detected.

Methods and systems for determining a base field prover volume of a field prover include connecting together a transfer meter assembly, a master prover, and the field prover in series. A flow of fluid at a first flow rate is provided and a calibration sequence is performed at the flow rate. The calibration sequence includes counting pulses generated by the transfer meter assembly over a duration of each pass of the master prover and a pass of the field prover. An intermediate calibrated field prover volume is determined from a ratio of the field prover pulse count to the average master prover pulse count, multiplied by a base master prover volume. The calibration sequence can be repeated to provide at least three intermediate calibrated field prover volumes at the first flow rate. The calibration sequence can be repeated at different flow rates to arrive at the base field prover volume.

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.

Various embodiments of the present disclosure relate to methods and systems for measuring an injected fuel quantity during multipulse injection events in a common rail of a fuel system including a fuel pump to supply fuel to the common rail. The method, using a control unit, determines if each of the multipulse injection events in a normal operating condition includes a pilot pulse; in response to determining that the pilot pulse is included, obtaining an enforced separation value between the pilot pulse and the main pulse to emulate a single-pulse injection; while the fuel pump is temporarily shut off, performing a temporary enforced separation on a fraction of the multipulse injection events; measuring a pressure change in the common rail during the temporary enforced separation; and resuming the normal operating condition of the multipulse injection events after the pressure change is measured.

A method and system for correcting a fuel injection amount that injects fuel may include applying a current value for injecting a target fuel amount and injecting fuel under a driving condition in which fuel injection is blocked; determining a frequency analysis value for a pressure signal of the fuel pressure rail when the fuel is injected; determining a fuel amount difference corresponding to a difference value between the frequency analysis value and a reference frequency analysis value stored in a data storage in advance; and correcting a current value of the injector which is applied to inject the target fuel amount to remove the fuel amount difference.

A method for monitoring an injector for common-rail injection systems includes detecting an electrical signal indicative of a deformation of a diaphragm of a head plate having a reaction surface facing a control chamber of the injector and processing the deformation signal to determine characteristic data of the operation of the injector.

A fuel injector test machine is provided such that an injector is fixed on a test feature with a manually operable clamp.