Fuel High Pressure System In V8 Dfi Engines; Fuel Temperature Sensor - Porsche Cayenne V6 2008 Service Information

Fuel High Pressure System in V8 DFI Engines

The fuel high pressure system in V8 DFI engines is made up of the these
parts/components.
Technical Manual
Always read and observe the specifications in the Technical Manual
when securing all fuel lines in the high pressure area.
Fuel Temperature Sensor (on low pressure side)
At start of production, all Cayenne V8 engines have a fuel temperature
sensor on the low pressure side, which will be replaced by a tempera-
ture model in the DME in later production. Depending on the amount of
fuel required and the fuel temperature, the DME control unit, together
with the flow control valve, regulates the amount of fuel on the high
pressure side upstream of the high pressure injectors.
Fuel High Pressure Pump
The fuel high pressure pump pumps the amount of fuel required for
injection and builds up a fuel pressure of up to 1740 psi (120 bar). The
axial piston pump is driven by the inlet camshaft. The Cayenne S and
Cayenne Turbo are equipped with different high pressure pumps.
Fuel, Exhaust & Engine Electrics
1 - Fuel high pressure pump with flow control
valve, pressure control valve and tempera-
ture compensator
2 - High pressure line
3 - Fuel rail
4 - Fuel pressure sensor
5 - Fuel line (for fuel injector on cylinder 1)
6 - Fuel injector (cylinder 5)
7 - Retainers for two fuel injectors
A - Low pressure fuel line
B - Fuel rail
C - Test port
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