Methods and systems are provided for reducing coking deposits in a fuel injection system. In one example, a method may comprise humidifying intake air of an intake system of an engine in response to a determination that fuel injector coking is occurring, or after a duration has passed since a most recent humidification event. A humidifying fluid, such as water, may be injected into the intake system to humidify the intake air, and the resulting humidified intake air may reduce and/or remove coking deposits on one or more direct fuel injectors of the fuel injection system.

A system and method are provided for evacuating fuel from a closed-loop fuel rail after engine testing. The method includes coupling a coaxial hose to a closed-loop fuel rail of an engine. The coaxial hose defines an outer tube section defining an outer passage and surrounding an inner tube section defining an inner passage, and a portion of the inner tube section is inserted a predetermined distance into the fuel rail. The method includes transferring fuel from a fuel supply through the outer passage of the coaxial hose and into the fuel rail for use during an engine testing procedure. After the engine testing procedure is complete, the method includes injecting compressed gas through the inner passage and into the fuel rail, creating a positive pressure. Residual fuel is evacuated from the fuel rail out through the outer passage of the coaxial hose.

A system and method are provided for evacuating fuel from a closed-loop fuel rail after engine testing. The method includes coupling a coaxial hose to a closed-loop fuel rail of an engine. The coaxial hose defines an outer tube section defining an outer passage and surrounding an inner tube section defining an inner passage, and a portion of the inner tube section is inserted a predetermined distance into the fuel rail. The method includes transferring fuel from a fuel supply through the outer passage of the coaxial hose and into the fuel rail for use during an engine testing procedure. After the engine testing procedure is complete, the method includes injecting compressed gas through the inner passage and into the fuel rail, creating a positive pressure. Residual fuel is evacuated from the fuel rail out through the outer passage of the coaxial hose.

A method of predicting manifold air pressure in an internal combustion engine during idle comprising the steps of receiving an idle air control (IAC) duty cycle value from an idle air controller, receiving an atmospheric pressure, and predicting a manifold pressure in an engine control unit based on the IAC duty cycle value and the atmospheric pressure.

An apparatus and a method for controlling a flow control valve for a high-pressure fuel pump include: a pressure sensor for fuel in a delivery pipe; a control unit for controlling an operation of a flow control valve by controlling a current applied to a coil; a power switching unit for supplying or blocking driving power supplied to the flow control valve based on a control signal of the control unit; and a current adjustment unit electrically connected/disconnected with the flow control valve by the power switching unit to reduce a current supplied to the flow control valve when the current adjustment unit is connected with the flow control valve. Therefore, a noise and a vibration by collision between the plunger and the core upon closing the flow control valve may be attenuated by adjusting a current amount applied to the coil.

A system for controlling actuation of an electromagnetic actuator includes an actuator having an electrical coil, a magnetic core, and an armature. A controllable drive circuit is responsive to an electric power flow signal for driving current through the electrical coil to actuate the armature. A control module includes an armature motion observer configured to determine an armature motion parameter in the actuator based upon a magnetic flux within the actuator and a predetermined mechanical equation of motion corresponding to the actuator and adapt the electric power flow signal based on the armature motion parameter.

The present invention discloses a carbon removing and cleaning device and method for an engine fuel nozzle and a combustion chamber of an automobile. The carbon removing and cleaning device comprises a fuel supply pipeline provided with a quick joint and a fuel line connection arranged in the front of the engine fuel nozzle; and a tee joint is connected between the quick joint and the fuel line connection, the quick joint is connected with a first inlet of the tee joint, an outlet of the tee joint is connected with the fuel line connection, a second inlet of the tee joint is connected with a pressurized cleaning agent tank, an electric control cleaning agent nozzle is arranged between the second inlet and a connecting port of the cleaning agent tank, and the pressure of a cleaning agent in the cleaning agent tank is larger than the fuel supply pressure of a fuel supply pipeline. The carbon removing and cleaning device is simple in structure, the cleaning agent can be directly mixed into fuel through a tee additionally arranged in a fuel delivery pipeline, and dynamic mixing ratio control can be performed by virtue of the electric control cleaning agent nozzle, so that a satisfied cleaning effect for the fuel nozzle and the top of a piston is achieved under the conditions that the stable idling operation of the engine is maintained, a proper amount of cleaning agent is input and the cleaning time is reasonable.

Methods and systems for fuel system leak detection using passive canister vent valves are disclosed. In one example approach, a method comprises generating engine off vacuum or pressure in a fuel system for leak diagnostics, where the pressure and vacuum are held via first and second mechanical relief valves positioned in parallel with one another and without a valve holding current.

Novel compounds can be used as additive packages for improving the cleanliness of direct injection spark ignition (DISI) engines.

A controller may obtain data indicative of heat release in a cylinder of an engine. The controller may determine that the data indicative of the heat release in the cylinder is indicative of clogging of one or more ducts of a duct structure of the engine. The controller may perform an operation to reduce the clogging of the one or more ducts based on the data indicative of the heat release in the cylinder being indicative of the clogging of the one or more ducts. The operation may include at least one of causing a pressure of fuel that is supplied to a fuel injector to increase or causing a peak temperature in the cylinder to increase.