The Unit Pump System (UPS) is a system for diesel direct injection. It is closely related to the Unit Injector System (UIS) and is exclusively available for commercial vehicles.The feature of the UPS is that each engine cylinder has a unit pump of its own. This consists of the high-pressure pump with integrated solenoid valve, a short injection fuel-injection line, a pressure-delivery connection and a conventional nozzle-and-holder assembly.

The advantage of this system: it permits injection pressures of up to 2,200 bar. In addition, conversion from injection systems with traditional in-line or distributor fuel-injection pumps does not require complete redesign of the cylinder head. Engine manufacturers save development costs. A further advantage: damaged pump/valve units are easily to exchange.

The Unit Pump System particularly used in commercial vechile diesel engines with performance of up to 92 KW per cylinder and 4 to 18 cylinders.A second control unit is required if the number of cylinders exceeds eight.

The Delphi Diesel Electronic Unit Pump is suitable for nine to 16 liter heavy duty diesel engines for on- and off-highway applications.