Two generations of VP44 pumps

The Opel brand has priority in the use of a Bosch type VP44 radial distributor injection pump. In 1996 r. Astra has left the factory gates 2.0 DI 16V with the first injection system, which could feed fuel into the combustion chamber at a pressure exceeding 1000 barium. VP44 injection pumps are found in Audi passenger cars, Ford, Opel and BMW. In turn, the VP30 axial distributor pump is used in Ford cars: Focus, Mondeo and Transit versions with lower engine power. A final example of a successful VP44 pump application is the motor 2.2 DTI in the Signum model.
The VP44 pump, together with the VP30 pump, belongs to the family of electronically controlled distributor injection pumps by Bosch, in which the injection dose is controlled by a high pressure solenoid valve. With this valve they are determined: start and end of injection pump pumping and injection dose. The difference between VP44 and VP30 is this, that in the VP30 high pressure is generated by the axial piston pump, and in VP44 – pump with two or three radial pistons. Using the axial pump, it is possible to pressurize the injector up to a maximum of 120 Mpa, and with radial pistons – up to 180 Mpa. Double activation of the high pressure solenoid valve, e.g. in the new Ford Mondeo engine and in the V6-TDI engine of the VW concern, enables pre-injection, which contributes to a soft combustion process and reduction of NOx emissions.

The operation of the VP pump is managed by the electronic engine control system EDC (Electronic Diesel Control). The first chips required two drivers: the MSG engine control unit and the PSG injection pump control unit. Later, one common controller mounted directly on the pump began to be used.