A method and system of periodically cycling an air shutoff valve, upon a pre-determined length of time elapsing since the last valve cycle; or upon the cumulative run time of an engine since the last valve cycle exceeding a pre-determined value.

This disclosure provides system and method that can determine hydraulic start of injection (SOI) in engines using an in-cylinder pressure sensor. The system and method determine apparent heat release rate (AHRR) curve data for the cylinder from the pressure information provided by the in-cylinder pressure sensors, and the hydraulic SOI from the derivative of the AHRR curve data. The system and method provide diagnostic, control and/or compensation opportunities for fuel injector operation in high pressure fuel rail engine systems without use of expensive or complex fuel injector components.

The subject matter of this specification can be embodied in, among other things, an apparatus that includes a high-pressure pump having a pump element, a regulating device positioned upstream of the high-pressure pump, a fuel channel defined between an inflow side of the regulating device and the pump element, and a safety device, actuatable to reduce a through-flowable cross section of the fuel channel.

A fuel injection valve drive control device includes a boost circuit having a boost coil, a switching component (FFT or the like) supplying a switching current from a battery source voltage to the boost coil, and a boost capacitor accumulating a boosted voltage generated by the operation of the switching component; a discharge circuit for discharging the accumulated electric charge via a current limiter (e.g. discharge resistor, constant current source) and a discharge switch (FET or the like); and a monitoring circuit for monitoring the accumulated voltage. The discharge circuit is caused to operate when the control device is shutting down and performs a deterioration/failure diagnosis of the boost capacitor and an operation check of the discharge circuit on the basis of a monitored voltage value of the boost capacitor at starting the discharge operation and a monitored voltage value of the boost capacitor after a predetermined time has elapsed.

A controller for controlling an internal combustion engine includes a valve timing adjuster, a variable valve lift mechanism and a processor. The processor controls a duty cycle of a drive signal in a selected one of control modes, thereby changing a relative rotational phase of a camshaft relative to an engine output shaft. The control modes include a specific control mode in which the duty cycle of the drive signal is adjusted to change a value of the current through a first motor. The processor performs, when changing the relative rotational phase through execution of the specific control mode, an abnormality diagnosis for the variable valve lift mechanism based on a comparison between the current value at the first motor and a reference current value. The processor sets the reference current value in accordance with a rotation angle of the output shaft of a second motor.

Various methods and systems are provided for health assessments of a fuel system. In one example, a method for an inlet metering valve (IMV) includes reducing electrical driving of the IMV, monitoring a response time of the IMV in real-time responsive to the reducing, and determining if the IMV is degraded based on a response of IMV current over a duration, the duration beginning after an initial decrease in current caused by the reducing.

An internal combustion engine includes a port injector that injects fuel into an intake port and a direct injection injector that injects fuel directly into a combustion chamber. When the internal combustion engine is in a low load condition while requiring fuel injection, a controller stops fuel injection through the port injector so that an entire required fuel injection amount is injected through the direct injection injector. As a result of this processing, the fuel pressure of the direct injection injector is reduced quickly in the low load condition.

A fluid injector comprising a coil arranged to drive a pump from a first state to a second state when energized, so as to pump a dosing fluid; a PN junction electrically arranged across the coil to discharge energy stored in the coil when the voltage across the coil is above a threshold. In one particular embodiment, the fluid injector is a selective catalytic reduction dosing fluid injector.

A method for detecting an opening time of a valve, includes receiving a valve current profile of the valve and processing the valve current profile using at least a slope reflection detector to determine a status of the valve based on an output of the slope reflection detector.

An engine control apparatus is equipped with a fuel injection amount computation unit, a determination process unit, and an engine abnormality process unit. The determination process unit determines, based on a deviation between a command injection amount and a monitoring injection amount, whether or not there is an abnormality in fuel injection control. An injection amount threshold, which is used to make a determination on an abnormality in fuel injection control, is set larger based on a vehicle speed-associated parameter when the vehicle speed-associated parameter is a value corresponding to a case where a vehicle speed is high than when the vehicle speed-associated parameter is a value corresponding to a case where the vehicle speed is low.