An add-on fuel injector control system and method for modifying a fuel injector pulse width for an electronically-controlled internal combustion engine is provided, which intercepts a pulse from an engine control unit (ECU) to a fuel injector, determines the optimal operational band, and either sends a modified or unmodified control signal pulse width to the fuel injector, depending on the band determination. The pulse width is increased by a total fuel adder. If the ECU control signal is determined to be in the auto-tune band, the controller modifies the output pulse width based on a comparison of current and previous values correlated to the rate of change of acceleration and whether the previous total fuel adder included an addition or subtraction of an auto-tune adder.

A fuel injector for an internal combustion engine is disclosed. The fuel injector is installable in a cylinder head bore of a cylinder head of the engine and has a body region arranged to be received within the cylinder head bore, and a head region arranged to extend outside the cylinder head bore to protrude from the cylinder head when the injector is installed in the cylinder head bore. The injector includes a first valve needle arranged to control the injection of a gaseous fuel from a first outlet, a second valve needle arranged to control the injection of a liquid fuel from a second outlet, a gaseous fuel inlet for admitting the gaseous fuel to the injector, and a liquid fuel inlet port for admitting the liquid fuel to the injector. The gaseous fuel inlet is disposed in the body region of the injector, and the liquid fuel inlet port is disposed in the head region of the injector. The injector can also include an internal accumulator volume so that an external fuel rail is not necessary.

A metering system for a fluid atomizer includes a housing, first and second metering members, and at least one solenoid. The housing includes a mixing chamber. The first metering member is operable to control flow of a first fluid to the mixing chamber. The second metering member is arranged coaxial with the first metering member and operable to control flow of a second fluid to the mixing chamber. The at least one solenoid is configured to operate at least one of the first and second metering members.

A method of refurbishing a fuel injector body valve seat. The method includes removing a poppet valve from the valve bore guide, machining the bore and valve seat to remove cavitation, machining to create an undercut a the stress riser, nitriding the valve bore guide and radiusing fuel passage to a sufficient depth to restore hardness thereto.

A system for detecting valve seating in a valve system such as a fuel admission valve system includes seat detection circuitry coupled with a low-side driver circuit in solenoid actuator circuitry for the valve system. The seat detection circuitry includes a voltage probe for sensing voltage in the solenoid actuator circuitry, delay circuitry, and a comparator coupled with the delay circuitry and the voltage probe and having an output dependent upon change in the sensed voltage over time. A timing of voltage changes is observed to enable valve seating detection.

An add-on fuel injector control system and method for modifying a fuel injector pulse width for an electronically-controlled internal combustion engine is provided, which intercepts a pulse from an engine control unit (ECU) to a fuel injector, determines the optimal operational band, and either sends a modified or unmodified control signal pulse width to the fuel injector, depending on the band determination. The pulse width is increased by a total fuel adder. If the ECU control signal is determined to be in the auto-tune band, the controller modifies the output pulse width based on a comparison of current and previous values correlated to the rate of change of acceleration and whether the previous total fuel adder included an addition or subtraction of an auto-tune adder.

A fuel injector for an internal combustion engine is disclosed. The fuel injector is installable in a cylinder head bore of a cylinder head of the engine and has a body region arranged to be received within the cylinder head bore, and a head region arranged to extend outside the cylinder head bore to protrude from the cylinder head when the injector is installed in the cylinder head bore. The injector includes a first valve needle arranged to control the injection of a gaseous fuel from a first outlet, a second valve needle arranged to control the injection of a liquid fuel from a second outlet, a gaseous fuel inlet for admitting the gaseous fuel to the injector, and a liquid fuel inlet port for admitting the liquid fuel to the injector. The gaseous fuel inlet is disposed in the body region of the injector, and the liquid fuel inlet port is disposed in the head region of the injector. The injector can also include an internal accumulator volume so that an external fuel rail is not necessary.

A system for detecting valve seating in a valve system such as a fuel admission valve system includes seat detection circuitry coupled with a low-side driver circuit in solenoid actuator circuitry for the valve system. The seat detection circuitry includes a voltage probe for sensing voltage in the solenoid actuator circuitry, delay circuitry, and a comparator coupled with the delay circuitry and the voltage probe and having an output dependent upon change in the sensed voltage over time. A timing of voltage changes is observed to enable valve seating detection.

An internal combustion engine has a water-cooled intercooler cooling intake air turbocharged by a turbocharger. The intercooler has an HT intercooler into which HT cooling water passing through a cylinder block is introduced and an LT intercooler into which LT cooling water lower in temperature than the HT cooling water is introduced and the LT intercooler is arranged to abut against an intake downstream side of the HT intercooler. A target LT temperature is set to a high temperature-side target value in a case where a temperature of the HT cooling water flowing into the HT intercooler is lower than a target HT temperature correlated with warm-up completion and the target LT temperature is set to a low temperature-side target value in a case where the temperature of the HT cooling water is equal to or higher than the target HT temperature.

A metering system for a fluid atomizer includes a housing, first and second metering members, and at least one solenoid. The housing includes a mixing chamber. The first metering member is operable to control flow of a first fluid to the mixing chamber. The second metering member is arranged coaxial with the first metering member and operable to control flow of a second fluid to the mixing chamber. The at least one solenoid is configured to operate at least one of the first and second metering members.