The document discusses the components and operation of electronic fuel injection (EFI) systems. It describes the basic construction of EFI including the fuel system components like fuel pumps, fuel filter, pressure regulator and injectors. It also explains the air induction system involving the throttle body, air valve and air intake chamber. Furthermore, it outlines the electronic control system for EFI covering the air flow meter, throttle position sensor, oxygen sensor and other sensors as well as the injection timing and volume control functions.