Fuel injection units were used in particular by Volkswagen and truck manufacturers – eg. Volvo
TT UK » Academy » Pump-Injectors – principle of operation
Power supply systems of high pressure engines equipped with fuel injection units were used particularly in cars manufactured by Volkswagen. Fuel injection unit is a device which incorporates an injector and a high pressure pump. Elimination of high pressure lines allows for obtaining injection pressure exceeding 200 MPa. Each engine cylinder is supplied with separate fuel injection unit fastened on the head, driven directly by a lifter or indirectly by a lever from the camshaft. Fuel dose and injection angle are regulated individually for each fuel injection unit by means of a valve which is electrically controlled. In consequence, engines equipped with this type of power supply, have low fuel consumption and good dynamics, at the same time emitting low amount of toxic exhaust fumes.