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Removing and installing fuel rail (bottom section of intake manifold) > < Dismantling and assembling fuel rail with injectors (engine code BAG)

A3 Mk2

Dismantling and assembling fuel rail with injectors (engine codes BLP and BLF)
Dismantling and assembling fuel rail with injectors (engine codes BLP and BLF)
  WARNING
Fuel supply line is pressurised. Before loosening fuel connections always release fuel pressure prior to carrying out any work → Chapter.
On engines with code letters BLP and BLF a fuel pressure limiting valve is incorporated in the fuel filter. In this system, only the supply pipe is routed to the front, to the engine compartment. The fuel pressure limiting valve opens when the pressure in the fuel supply line rises above 6 … 6.8 bar. Excess fuel flows from the filter directly back to the fuel tank via a return line.
   
1 - Bolt
q   10 Nm
2 - Mechanical single-plunger high-pressure pump with fuel pressure regulating valve -N276-
q   The high-pressure fuel pump should only be removed and installed when the engine is cold.
q   The fuel system must not be under pressure. For procedure, refer to → Chapter.
q   When installing the high-pressure fuel pump, it is essential to ensure that no dirt enters the fuel system.
q   Install pipes free of tension.
q   Removing and installing → Chapter
3 - Fuel pressure sender for low pressure -G410-
q   Not fitted on models with engine code BLF
q   Fitting location: in fuel supply pipe
q   18 Nm
4 - Fuel supply pipe
5 - Bolt
6 - Fuel return pipe
7 - Support ring
q   Make sure it is correctly seated
q   Via this support ring, the fuel rail exerts the force which holds the injector in the cylinder head.
8 - O-ring
q   Renew
q   When installing lubricate lightly with clean engine oil
9 - Injector
q   Removing and installing → Chapter
10 - Combustion chamber ring seal (teflon ring seal)
q   Renewing → Chapter
11 - Fuel rail (bottom section of intake manifold)
q   Before removing and installing, lock vacuum unit in position using a 2.5 mm drill → Chapter.
q   After installing new bottom section of intake manifold remove clip for vacuum unit.
q   After installation, check function of intake manifold flap (air flow control flaps) using hand-operated vacuum pump -VAS 6213- → Chapter
q   Removing and installing → Chapter
12 - Union nut
q   18 Nm
13 - High-pressure fuel pipe
14 - Bolt
15 - Union nut
q   18 Nm

   

Removing and installing fuel rail (bottom section of intake manifold) > < Dismantling and assembling fuel rail with injectors (engine code BAG)