A throttle body assembly for a combustion engine includes a throttle body having a pressure chamber including a supply of liquid fuel, and a throttle bore with an inlet through which air is received. A throttle valve is carried by the throttle body with a valve head movable relative to the throttle bore. A metering valve is coupled to the throttle body, and has a valve element that is movable between open and closed positions. A boost venturi is located in the throttle bore and has an inner passage that is open at both ends to the throttle bore. The boost venturi has an opening through which fuel flows into the inner passage when the valve element is in the open position, wherein fuel flows from the pressure chamber to the metering valve under the force of gravity or under a pressure of less than 6 psi.

A metering system for a fuel atomizer includes a housing having a fuel inlet and an oxidizer inlet arranged coaxially, and an oxidizer metering device having a plurality of oxidizer channels, an oxidizer flow controller, and a fuel metering device. The oxidizer channels are spaced apart circumferentially in the housing and are arranged angled in at least one of a radially inward direction and a tangential direction to create a swirl of oxidizer flow in a mixing chamber of the fuel atomizer. The oxidizer flow controller is configured to control flow of oxidizer from the oxidizer inlet to the plurality of oxidizer channels. The fuel metering device is configured to control fuel flow from the fuel inlet to the mixing chamber.

In a combustion cycle in which fuel for forming a homogenized air-fuel mixture in the combustion chamber is injected from the first fuel injector, ignition-use fuel for forming an ignition-use air-fuel mixture in the vicinity of the electrode part is injected from the second fuel injector, and lean combustion is performed by an excess air rate of 2.0 or more, the ignition-use fuel is injected by at least an injection rate of 1.0 mm.sup.3/ms or more for a duration of 250 μs or more in an interval from a crank angle advanced by exactly 20 degrees from an ignition timing of the spark plug to the ignition timing, and the quantity of the ignition-use fuel is 2.0 mm.sup.3/st or less.

An injection device for an internal combustion engine having a first injection system for injecting fuel having a first fuel composition, and a second injection system for the injection of fuel having a second fuel composition that has a lower ethanol component than the first fuel composition, the first injection system having at least one first fuel injector for injecting fuel having the first fuel composition both in the direction of a first intake orifice of a combustion chamber of the internal combustion engine, and in the direction of a second intake orifice of the combustion chamber, in which the second injection system has a second fuel injector for injecting fuel having the second fuel composition essentially only in the direction of the first intake orifice, and a separate third fuel injector for injecting fuel having the second fuel composition essentially only in the direction of the second intake orifice.

A throttle body fuel injection system and method that is arranged to easily replace four-barrel carburetors includes a throttle body assembly with four main bores, each with a throttle plate and an associated fuel injector. Each injector feeds fuel into a circular fuel distribution ring via a fuel injection conduit, which introduces pressurized fuel into the air stream. The fuel distribution rings and bores have profiles that avoid constrictions for to prevent low pressure zones according to the Venturi effect. The throttle body includes an idle air control circuit having a port opening into main intake bores downstream of the point of fuel distribution into the air stream, thereby reducing the tendency for a lean fuel mixture at idle. An ECU “feed forward” algorithm controls fuel injection as a function of the position of the idle air control valve.

A vehicle includes a residual pressure holding valve provided downstream a feed pump of a fuel to hold a pressure in a fuel pipe leading to the port injection valve. Residual pressure holding valve is opened to return the fuel in the fuel pipe to the fuel tank when the pressure in the fuel pipe exceeds a valve opening pressure, and closed when the pressure in the fuel pipe is lower than the valve opening pressure. At the time of a request to reduce a target pressure of the fuel to be supplied to the electric feed pump, a control device refrains from causing the target pressure to decrease when a load of the engine is smaller than a prescribed value, and causes the target pressure to decrease when the load of the engine is greater than the prescribed value.

Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.

Fuel in a fuel tank is supplied by a low-pressure pump to intake passage injectors mounted on an intake manifold via a low-pressure fuel supply pipe and a low-pressure fuel distribution pipe. A high-pressure pump is provided on the low-pressure fuel supply pipe. The pressure of the fuel is boosted by the high-pressure pump, and then is supplied to in-cylinder injectors via a high-pressure fuel distribution pipe. In an intake passage injection (MPI) mode, excitation of a solenoid is stopped and operation of an electromagnetic spill valve is stopped so as reduce vibration and noise caused by the seating of the electromagnetic spill valve in a valve seat.

A throttle body fuel injection system including a throttle body with at least one air intake, a fuel injector coupled to the throttle body at a fuel port and an annular ring coupled to the cylindrical inner wall of the air intake. The annular ring includes a primary fuel discharge orifice adjacent to the fuel port and a plurality of secondary fuel discharge orifices arranged radially around the annular ring for spraying atomized fuel into the air intake.

A fluid mixing device that includes a housing having a fuel inlet and at least one primary orifice positioned at the inlet, wherein the at least one orifice configured to disperse a stream of fuel into a plurality of fuel droplets. The plurality of fuel droplets contact a fuel impingement surface to break up the plurality of fuel droplets into a plurality of smaller secondary droplets and create a thin film of secondary droplets on the impingement surface. At least one pressurized air channel delivers an airflow into contact with the secondary droplets. The secondary droplets pass through a plurality of secondary outlet orifices to exit the housing. A size of the plurality of secondary droplets is reduced when passing out of the plurality of secondary orifices.