26
Engine
Pressure regulation
The fuel filter is bolted to the exterior of the fuel tank. The pressure regulator is integrated in the fuel filter.
In case of excess pressure, the governed fuel is returned to the tank. The pressure regulator in the FSI engine
cuts off fuel delivery at 6.4 bar (relative). In the case of the MPI engine, fuel cut-off is at 4 bar (relative). Both
systems are returnless, with the distinction being that the pressure in the MPI engine is maintained at
a constant 4 bar, while the FSI engine utilises a supply-on-demand fuel system.
380_021
For the MPI and FSI engines, a fuel delivery unit with
integrated fuel gauge potentiometer and a suction
jet pump are arranged inside the fuel tank.
Fuel gauge sender
Fuel pump
Suction jet pump
In the case of the quattro tank, a second fuel gauge
potentiometer is arranged inside the second half of
the fuel tank.The second half of the fuel tank also
houses the suction jet pump, which pumps the fuel
into the fuel delivery unit reservoir. The suction jet
pump is attached securely to the sender flange by
means of clips. The thin line is the propulsion jet
line. It is driven by the suction jet pump. The thicker
line is the mixing tube, in which the intake fuel is
pumped to the fuel delivery unit.
The fuel gauge senders are configured as slider
potentiometers.
380_023
Suction jet pump
Fuel gauge sender
Reference
Pressure regulation in the 3.2l and
2.0l engines is described in Self-
Study Programme 290 and Self-Study
Programme 332 respectively.
