Pump-Nozzle Injection Technology
Diesel engines using pump-nozzle injection technology are the most efficient internal combustion engines. Each cylinder in the engine is fitted with a pump-nozzle unit which generates a high injection pressure of up to 2,400 bar and injects exactly the right amount of fuel at the right moment. Mounting the units in the cylinder head dispenses with the high pressure lines used in conventional distributor injection pumps. The pressure increase is achieved mechanically. A small plunger is operated by an additional cam on the valve camshaft. The cam is shaped to give the speed necessary to build the desired high pressure fast. A solenoid valve controls the injection timing and the pressure cannot increase until the valve is closed (electrically). The valve's fast closure gives a sharp cut-off to the injection, vital for clean and complete combustion. The result is lower emissions, improved fuel consumption and higher power output.