Common Rail Diesel Injection Systems consist of the following main components, a high-pressure pump, piezo injectors, rail, lines, and engine control unit. The high-pressure pump continually delivers diesel fuel into the rail under pressure, the rail supplies fuel to the piezo injectors through the lines. The engine unit controls the piezo injectors to ensure that the right amount of diesel fuel is injected into the cylinder at the right point in time. VDO is a leading worldwide manufacturer and distributor of automotive technologies and parts, often chosen by OE manufacturers as the primary source for components.