A fuel injector assembly in an engine having a plurality of cylinders and intake passages opening respectively into the cylinders includes a housing mounted in each of the intake passages, and a plurality of solenoid-operated fuel injection valves connected to a fuel supply source for injecting fuel through the intake passage into each of the cylinders. The solenoid-operated fuel injection valves are accommodated in the housing. The housing has a magnetic shield layer such as an air gap disposed between the fuel injection valve means. The fuel injection valves are supplied with fuel from the fuel supply source through a common fuel supply passage defined in the housing.

A fuel injection type two-cycle engine for motorcycles. A fuel injection valve for injecting fuel into an air intake passageway at a predetermined timing is disposed on the upstream side of a reed valve in the air intake passageway communicating with an interior of the engine via the reed valve, with the injection port thereof directed towards the reed valve. An air intake pipe forming the air intake passageway extends nearly in the vertical direction from the upper surface of a crank case at an middle position between a crank shaft extending in the widthwise direction of the vehicle body and a transmission shaft separated from the crank shaft in the back and forth direction and extending in the widthwise direction of the vehicle body, and a fuel injection valve protrudes from this air intake pipe in the back and forth direction. The air intake pipe and the fuel injection valve are positioned between left and right vehicle body frame members above the engine, and a partition plate is provided between the vehicle body frame members and the engine main body.

In order to make the quantity of fuel in a cylinder approach a requested value with high accuracy, the characteristic of fuel transport is employed by use of a model in which all injected fuel adheres onto walls of the intake manifold and then a part of the fuel adhering to the walls is sucked off into the cylinder. By use of a respective model for each cylinder, the quantity of fuel injected into each cylinder is independently controlled so that the quantity of fuel in the cylinder is established to be a requested value.

The present invention is directed to a fuel vaporizer and system. The fuel vaporizer comprises a fuel injector and a pair of facing nozzle sections for mixing the fuel/air mixture. Further, the internal configuration of the vaporizer and the directing of the incoming air stream into the vaporizer creates a vortex flow within the fuel vaporizer in combination with preheating and pressuring the fuel to facilitate a high degree of mixing within the vaporizer. The vaporizer and system can be added to an existing carbureted or fuel injected system of an internal combustion engine.

An internal combustion engine has a common shared intake port for each pair of cylinders and having a primary fuel injection system capable of controlling very precisely the distribution of fuel into each cylinder by controlling the duration and timing of each injection pulse. A common fuel injector is provided for each shared intake port and is controlled so as to inject fuel into the shared intake port only during the specific intake strokes of individual cylinders. Each injector preferably takes the form of an electronic fuel injector coupled to a controller receiving signals from engine mounted sensors such as a crank angle indicator. Such electronic control permits very precise control of the duration and timing of the fuel injection pulse and also enables other injection strategies such as a skip-fire operation in which fuel injection is withheld during selected intake strokes of selected cylinders, thereby eliminating firing cycles corresponding to the selected intake strokes. The fuel injection system is usable with both compression ignition and spark ignition engines and may employ additional primary injectors and/or liquid fuel pilot injectors.