Passat Sedan L4-1896cc 1.9L DSL Turbo (1Z) (1997)
Fuel Injector: Description and Operation
Diesel injectors spray fuel directly into the combustion chamber near the end of each compression stroke. The injectors are threaded into the
cylinder head and are subject to the direct heat of combustion like a gasoline engine spark plug. Each injector is protected by a heat shield between
the cylinder head and injector body. The heat shield acts as an insulating and sealing washer.
Fuel pressure from the injection pump into these dual spring injectors, forces the needle up against spring pressure, in two stages, so that the
injector sprays a cone-shaped mist of diesel fuel at the proper time. A small quantity of fuel leaks around the injector needle to lubricate and cool
the injector. This fuel returns to the tank through a separate fuel line.