Z Series E85 Z4 3.0i (M54) ROADST
E85 fuel supply system (spark-ignition engines)
General function description for fuel systems.
2. Parts designation
1. Fuel tank (plastic)
12. Non-return flap
2. Surge chamber
13. Fuel feed line
3. Electric fuel supply pump
14. Fuel rail
4. Suction jet pump
15. Carbon canister (AKF)
5. Fuel filter with pressure regulator
16. Purge air line
6. Fill level limiting valve (rollover valve)
17. Tank vent valve (TEV)
7. Overpressure safety valve
18. Intake manifold
8. Service vent valve (rollover valve)
19. Engine control unit (DME)
9. Vent line
20. Tank leakage diagnostic module (USA only)
10. Mushroom valve
21. Dust filter (USA only)
11. Fuel filler pipe
A: Max. fuel tank fill height
3. Function description (see also drawing 5.1 / 5.2)
The saddle-shaped fuel tank contains the surge chamber with integrated electric fuel supply pump and level sensor on
its right side.
The surge chamber ensures that the fuel supply pump is properly supplied in all vehicle operating states.
The fuel is pumped from the right side of the fuel tank into the surge chamber via the suction jet pump integrated in the
The fuel in the left tank half is repumped via a second suction jet pump from left to right.
Return line, pressure regulator and fuel filter are located in the tank.
The non-return flap prevents fuel from splashing back in the filler pipe after shutdown of the petrol/gas pump nozzle.
Fuel supply to engine:
M54 ECE / Japan / USA (see drawing 5.1, 5.2):
The fuel is routed from the electric fuel supply pump via the fuel filter and the fuel feed line to the fuel rail.
Pressure regulator and fuel filter are incorporated in a single unit in the tank. This removes the need for a fuel return
The fuel passes through the pressure regulator into the left side of the fuel tank and thereby drives a suction jet pump.
This pump repumps the fuel from the left side of the tank to the right side.
The fuel rail is return-free.
Venting system USA (see drawing 5.2)
The fuel tank is vented during refueling via the vent line.
Because of its large cross-section, the vent line directs the displaced volume (fuel vapors) at high speed to the carbon
RA E85 fuel supply system (spark-ignition engines)
BMW AG - TIS
Issue status (12/2007) Valid only until next DVD is issued
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