Fuel Injection System - Diesel: Description
The Mazda diesel pickup fuel injection system consists of a combination injection pump and fuel distributor, 4 fuel injection nozzles, a fuel filter with an integral priming pump, a water separator (sedimentor), fuel lines, and the fuel tank. The engine is also equipped with a glow plug system to assist in cold starting.
The injection pump is a vane type pump and is driven by the engine timing gears. An altitude compensator and a cold start device are installed on the pump to modify injection duration as necessary. The distributor portion of the pump contains a fuel cut solenoid to stop fuel flow to the injectors after the ignition switch is turned off. See Fig 1 .
The injectors use a needle type valve at the end of the nozzle. Injector opening pressure can be changed by adding or subtracting adjusting shim thickness. The adjusting shim is located just above the needle valve return spring in the injector.
The glow plug system consists of a glow plug in each cylinder, 2 relays, a ballast resistor, a glow plug control unit as well as various switches and warning lights.
The water separator (sedimentor) collects excess water and dirt in the fuel system. A water detector is mounted on the top of the water separator. The detector will turn on a warning light on the instrument panel when the water level reaches a predetermined level.