Diesel Fuel Injection: Description

A piston-type fuel feed pump, driven by fuel injection pump, draws fuel from tank. After passing through a constant volume filter, fuel is delivered to injection pump. Pressurized fuel is then forced to injectors mounted in cylinder head. The injectors are lubricated by fuel leaking back past needle valve stems. Fuel used for lubrication is then returned to fuel tank by a leak-off pipe. Engine control is maintained by either a diaphragm or mechanical-type governor.