Fuel injection apparatus

Apparatus for injecting fuel into the intake manifold of an internal combustion engine having at least one combustion chamber with an intake port and having a first intake passage through which there is an air flow to said combustion chamber by said intake manifold, comprising:

• a second passage, separate from said first passage and having a venturi-like constriction;
• a pump following said constriction in said second passage, for drawing a continuous stream of air through said second passage, said pump having an output at a pressure which is greater than the pressure in said intake manifold;
• fuel proportioning means comprising a fuel reservoir wherein fuel is maintained at a constant level, a first orifice communicating with said air passage constriction, and a second variable cross-section orifice, arranged between said first orifice and said fuel reservoir;
• means, responsive to the rate of air flow in said first passage, for controlling the opening of said second orifice;
• and means for supplying the pressurized fuel carrying air stream from said pump to said intake manifold adjacent said intake port.