Fuel Injectors/High Pressure Injectors - Porsche Cayenne V6 2008 Service Information

Fuel, Exhaust & Engine Electrics

Fuel Injectors/High Pressure Injectors

The electromagnetically operated fuel injectors are located in the
cylinder head. They are activated by the Motronic control unit in accor-
dance with the firing order. Following activation, they inject fuel directly
into the combustion chamber at a pressure of 580 psi (40 bar) to 1740
(120 bar). The injectors for both cylinder banks are on the intake side of
the cylinder head. This arrangement allows the injectors for cylinders 1,
3 and 5 to run through the inlet port on the cylinder head. The injectors
for cylinder bank 1 are therefore longer than the injectors for cylinder
bank 2.
Since the injectors are inserted from the same side for both cylinder
banks, the piston recesses of cylinder bank 1 and 2 must be molded
differently so that the injected fuel is whirled around and mixed perfectly
with the air that is drawn in. This is necessary because the fuel injectors
and intake valves on both cylinder banks are arranged in different
angles.
In addition to the amount of fuel injected and the injection time, the
shape and alignment of the fuel jet is also important here. A defective
injector is detected by the misfire detection system and is not activated
again.
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