The illustration shows the high pressure pump with drive shaft for timing belt drive (1.4L Duratorq-TDCi (DV) diesel engine)
A Fuel return
B High-pressure connection
C Fuel feed
1 Fuel metering valve (partial view)
2 High pressure pump element (displacement unit)
3 Fuel pressure control valve
4 Eccentric
5 Drive shaft
6 Transfer pump
Note: Depending on the engine version, the high pressure pump is driven via the timing belt for camshaft drive (1.4L Duratorq-TDCi (DV) diesel engine) or via the exhaust camshaft (2.0L Duratorq-TDCi (DW) diesel engine). The design and function of the high-pressure pump are essentially similar.
Function of the high-pressure pump
The high-pressure pump provides the interface between the low and the high pressure systems. Its function is to always provide sufficient compressed fuel under all operating conditions and for the entire service life of the vehicle.
First, the fuel is drawn from the tank by the transfer pump integrated in the high pressure pump and delivered to the high pressure pump.
The high-pressure pump permanently generates the high system pressure for the fuel rail. Therefore, the compressed fuel does not have to be supplied under high pressure for each injection process individually, unlike systems with distributor type injection pumps.
The high pressure chambers are formed by three pump elements (displacement units), each offset by 120 degrees.
The fuel metering valve and the fuel pressure control valve are bolted/flanged to the high pressure pump housing. These ensure optimum control of the high pressure for the system.
Due to the permanently high system pressure, injection quality is optimized over the entire engine speed/load range.
