2. Construction and Operation of Components 2.1 Supply Pump [1] Outline The function of the supply pump is to regulate the fuel discharge volume, thus generating internal fuel pressure in the rail. [2] Construction The supply pump consists of a feed pump, similar to that of the conventional in-line pump, and the PCVs (pump control valves), provided at each cylinder, to regulate the fuel discharge volume. The supply pump uses a three-lobe cam to reduce the number of engine cylinders supplied by the pump to one-third (e.g. a two-cylinder pump for a six-cylinder engine).
Furthermore, smooth and stable rail pressure is obtained because the rate at which fuel is pumped to the rail is the same as the injection rate. PCV (Pump Control Valve) Gear of TDC sensor Feed pump Q000086E 3-lobe cam 6