Electromagnetically Controlled Distributor-Type Fuel Injection System

With the advent of electronic controls and development of electromagnetically controlled fuel injection pumps, the cost of fuel systems using plunger-type pumps was substantially reduced. Further reduction in cost can be achieved if fewer solenoid valves are used. A new type of injection pump combining electromagnetic spill control principle with distributor-type operation is described. Only one solenoid valve is required for a multi-cylinder engine. The pump was designed for port injection of gasoline, but with some modifications could be adapted to direct fuel injection. The fuel injection system includes a controller capable of electronic trimming of port-to-port fuel distribution for tight control of air to fuel ratios in all engine cylinders. A review of the basic concept and operating principles is given, and test results as well as cost considerations are discussed.