Audi 4.2-litre V8 FSI - Vacuum Hoses in the Audi RS4

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Air circulation system
Vacuum unit for combination valve
Secondary air pump
Intake manifold flap
air flow control valve
N316
Activated charcoal
canister
Vacuum units for
intake manifold flaps
Variable intake manifold
change-over valve N335
The conventional method of supplying vacuum to
the brake servo and the engine components is
problematic in the case of FSI engines.
Secondary air
inlet valve N112
Non-return valve
Air filter
Filter housing flap
B
A
Brake servo
relay J569
This means that connecting a vacuum line down-
stream of the throttle valve would offer little pros-
pect of success because, in many engine operating
situations, the wide open throttle valve would result
in low mass flow rates and vacuum in the intake
manifold being.
Vacuum hoses in the Audi RS4
Vacuum reservoir
Brake servo
Suction jet pump
(entrainment pump)
with integrated non-
return valve
Activated charcoal canister
solenoid valve 1 N80
Vacuum pump for
brakes V192
Hot-film air mass
meter
Non-return valve with
brake servo pressure
sensor G294