A fuel system for an internal combustion engine is provided including a first fuel container for a first fuel, a second fuel container for a second fuel, a pump, and a first fuel injector, the fuel system being arranged to provide a communication between the first fuel container and the pump and between the pump and the first fuel injector, and a reservoir with a separation device adapted to divide the reservoir into a first volume and a second volume, whereby the separation device may be moved or flexed by a pressure difference in the first and second volumes so as to change the sizes of the first and second volumes, wherein the fuel system is arranged to provide a communication between the pump and the first volume, and to provide a communication between the second fuel container and the second volume and between the second volume and a second fuel injector.

Methods and systems are providing for improving zero flow lubrication (ZFL) of a high pressure fuel pump coupled to direct fuel injectors via a direct injection fuel rail. A ZFL transfer function for the fuel pump is learned while fuel is at non-nominal fuel bulk modulus conditions and corrected for variations from a nominal fuel bulk modulus estimate. When zero flow lubrication of the pump is requested, the pump is operated with a duty cycle based on the learned transfer function and an instantaneous estimate of the fuel bulk modulus to compensate for differences in fuel condition from the nominal fuel bulk modulus estimate.

An internal combustion engine including a control device, at least one combustion chamber, and at least one injector for injecting liquid fuel into the at least one combustion chamber is provided. The injector can be controlled by the control device by means of an actuator control signal. An algorithm is stored in the control device, which algorithm receives the actuator control signal and using an injector model calculates the amount of liquid fuel that is discharged via the discharge opening of the injector and compares the amount of liquid fuel calculated by means of the injector model with a desired target value of the amount of liquid fuel. Depending on the result of the comparison, the control device leaves the actuator control signal the same or corrects it.

A method for controlling a dual fuel engine system includes determining a friction power loss amount of an internal combustion engine of the dual fuel engine system, where the friction power loss amount is based on an engine speed of the internal combustion engine and a friction torque estimate. The method also includes determining an accessory power loss amount of a power of the internal combustion engine, where the accessory power loss amount is based on the engine speed and an accessory torque estimate. The method further includes estimating a net engine power amount based on the accessory power loss amount and a brake power amount of the internal combustion engine, estimating an indicated diesel power, and estimating, based on the estimated net engine power, a first indicated engine power and a first gas power.

Disclosed are a fluid control system and method for controlling delivery of two variable pressure fluids to maintain a pressure bias between the two fluids within an end use device. The system employs an actively controlled vent valve which can be integrated into a fluid control module in preferred embodiments and is actuated to an open position to decrease fluid pressure in a first fluid supply line when a determined pressure differential reversal exceeds a predetermined threshold pressure differential reversal. The disclosed system is particularly useful in a high pressure direct injection (HPDI) multi-fueled engine system where the first fluid is a gaseous fuel and the second fluid is a liquid fuel. The fluid control system and method of controlling it provide for improved control of venting along with protecting system components from high back pressure and cross contamination of fluids.

An engine having at least a primary and secondary fuel supplies is configured to operate by determining a fueling mode for each of first and second groupings of cylinders, independently. A method, therefore, for operating the engine includes monitoring engine operating parameters with an electronic controller, determining an engine operating point based on the engine operating parameters, calculating a first operating mode of a first cylinder grouping based on the engine operating point, calculating a second operating mode of a second cylinder grouping based on the engine operating point, and selectively activating at least one of a diesel injector, a gaseous fuel injector and a spark device in each engine cylinder separately and selectively for each cylinder of the first and second cylinder grouping based on the engine operating point.

A gasoline Reid vapor pressure (RVP) detection system includes a fuel pump and a motor operating the fuel pump in a forward direction of rotation to feed a gasoline fuel to a vehicle engine. A control device is in communication with the motor selectively directing change from the forward direction of rotation to a reverse direction of rotation opposite to the forward direction of rotation. A pressure reduction device receives flow of the fuel during operation in the reverse direction of rotation and reduces a pressure of the fuel until fuel vaporization occurs. A pump speed at which vaporization of the fuel occurs at the pressure reduction device when a motor speed and a motor current change non-linearly is correlated to a fuel RVP.

A method of characterizing a mixed fuel flow period is provided. The method includes flowing a mixed fuel, the mixed fuel being comprised of at least a first fuel type and a second fuel type, the mixed fuel flow period being determined where the fuel is switched from the first fuel type to the second fuel type, determining a density of the first fuel type and a density of the second fuel type, and determining a total flow, the total flow being determined from the density of the first fuel type and the density of the second fuel type.

A system for remotely monitoring and controlling operation of a hydro-diesel engine, having: (a) a diesel engine assembly; (b) a hydro-diesel assembly connected to the diesel engine assembly; (c) a remote control system; and (d) a remote computer system in communication with the remote control system, wherein the remote computer system is configured to instruct the remote control system to turn off operation of either: (i) the hydro-diesel assembly while permitting the diesel engine assembly to continue operation while the hydro-diesel assembly is not operating, or (ii) both the hydro-diesel assembly and the diesel engine assembly.

An engine device (21) including: an intake manifold (67) configured to supply air into a cylinder (77), an exhaust manifold (44) configured to output exhaust gas from the cylinder; a gas injector (98) which mixes a gaseous fuel with the air supplied from the intake manifold; and a main fuel injection valve (79) configured to inject a liquid fuel into the cylinder for combustion. At the time of switching the operation mode from one to another between a gas mode and a diesel mode, a supply amount of a first fuel to be supplied in a post-switching operation mode is increased to a switching threshold value through an increase control which monotonously increases the supply amount, and then is controlled by a speed-governing control based on the engine rotation number. The switching threshold value is set based on the engine rotation number or the engine load.