Fuel, Exhaust & Engine Electrics
Page 2.23
V8 DFI Engines
Knock Sensors
All V8 DFI engines have four knock sensors arranged in the V of the
engine block. These four knock sensors are required for exact knock
detection in V8 DFI engines since stronger vibrations are transmitted to
the cylinder head via the fuel injectors during high pressure fuel
injection.
Ignition Coils
The Cayenne has static high-voltage ignition distribution with individual
ignition coils attached directly to the spark plugs. The newly enhanced
ignition coils in V8 DFI engines work according to the same principle as
previous V8 ignition coils.
This system offers the following advantages:
• High level of ignition safety.
• Minimum electromagnetic interference with other electronic
components.
• No requirement for ignition cables and distributor ignition.
The DME control unit activates the individual ignition coils individually in
the firing order 1-3-7-2-6-5-4-8 for each cylinder. Safer ignition
processes and therefore optimized power, together with minimized
emissions and fuel consumption are obtained as a result of the
measures and advantages described. All parts in this enhanced compo-
nent are installed as a complete unit in a special rod ignition module
housing. This is connected electrically and mechanically to the spark
plug in the spark plug recess via the short high-voltage plug. The com-
ponent is also secured mechanically using bolts. The ignition coil is
sealed at the four-pin plug and in the spark plug recess to protect it
from spray water.
To Next Page
Loading...
Need help?
General
