Abstract: A fuel injection system that includes an injector having a pintle movable within a housing for selectively opening and closing communication between inlet and outlet ports in the housing. The inlet port is connected to a source of fuel under pressure, while the outlet port is connected to a nozzle for delivering fuel under pressure to the engine. A section of magnetic material is coupled to the pintle, and a permanent magnet is mounted on the engine flywheel, such that magnetic forces imparted as the permanent magnet moves therepast moves the pintle against a spring to open communication between the inlet and outlet ports, and thereby deliver fuel under pressure from the source to the nozzle. A cam mechanism is rotatably positioned within the pintle housing and operatively coupled to the pintle for adjustably varying stroke of the pintle within the housing, and thereby varying time duration during which the injector opens communication between the fuel source and the nozzle.