Fuel supply system for turbocharged internal combustion engine

Abstract

An improved fuel supply system for a turbocharged diesel engine, of the general type comprising a fuel pump which conveys fuel at an intermediate pressure to a high-pressure distributor which has a fuel-injection timing piston that adjusts the injection timing as a function of the intermediate fuel pressure. The improved system includes a control unit which reduces the pressure applied to the timing piston when the engine is subjected to a demand for increased fueling at low turbocharger boost pressures. This causes the injection timing to be retarded, which in turn increases the exhaust temperature and pressure and, thus, increases the turbocharger boost pressure. After a controlled interval during which boost pressure has risen the desired amount, the control unit allows the pressure applied to the timing piston to rise back to its former value, whereupon the injection timing returns to normal.