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Checking injectors > < Injectors

A4 Mk3

Injectors - exploded view
   
Injectors - exploded view
  Caution
Risk of malfunctions caused by dirt.
Observe → Chapter „Safety precautions when working on the fuel system“.
1 - Support bracket
q   For clamping piece
q   Different tightening torques:
t  To camshaft bearing: 2.5 Nm
t  To cylinder head: 9 Nm
2 - Clamping piece
q   Mark allocation for re-installation; pay attention to marking when installing
q   Must be renewed if injector is renewed
3 - Bolt
q   14 Nm
4 - High-pressure pipe
q   From high-pressure pump to fuel rail
q   Do not alter shape
q   Check for damage before re-installing
q   Installing → Chapter
q   Lubricate threads of union nuts with clean engine oil
q   25 Nm
5 - Retaining clamp
q   For high-pressure pipe
6 - Bolt
q   9 Nm
7 - Retaining clamp
q   For high-pressure pipe
8 - Bolt
q   9 Nm
9 - High-pressure pipe
q   From fuel rail on opposite side
q   Do not alter shape
q   Check for damage before re-installing
q   Installing → Chapter
q   Lubricate threads of union nuts with clean engine oil
q   25 Nm
10 - Fuel rail
11 - Fuel return hose
q   To fuel tank
12 - Fuel return hose
q   From injectors
q   Do not dismantle
q   Renew together with restrictor
q   After renewing, engine must be run at idling speed for approx. 2 minutes to bleed fuel system
q   Then check fuel return hoses for leaks
13 - Ring connection for hose
14 - Banjo bolt
q   25 Nm
15 - Seals
q   Renew
16 - Fuel pressure regulating valve -N276-
q   With deformable sealing lip
q   Cannot be re-installed
q   Removing and installing → Chapter
q   Tightening torque → Fig.
17 - Bolt
q   22 Nm
18 - High-pressure pipe
q   From fuel rail to injector
q   Do not alter shape
q   Mark allocation for re-installation; pay attention to marking when installing
q   Check for damage before re-installing
q   Installing → Chapter
q   Lubricate threads of union nuts with clean engine oil
q   25 Nm
19 - Fuel return hose
q   From injectors
q   Do not dismantle
q   Renew together with restrictor
q   After renewing, engine must be run at idling speed for approx. 2 minutes to bleed fuel system
q   Then check fuel return hoses for leaks
20 - O-ring
q   Renew
21 - Injector
q   Mark allocation for re-installation; pay attention to marking when installing
q   Removing and installing → Chapter
22 - O-ring
q   Renew
23 - Copper seal
q   Renew

   
Fuel pressure regulating valve -N276- - tightening torque
–  Position fuel pressure regulating valve -N276- so that electrical wiring is not under tension when connector -arrow- is plugged in.
–  Tighten union nut on regulating valve in 4 stages as follows (counterhold hexagon flats on housing):
  A23-10534
StageTightening torque
1.Screw in by hand until it makes contact
2.60 Nm
3.Turn back by 90°
4.85 Nm

   
Fuel pressure sender -G247- - tightening torque
–  Tighten fuel pressure sender -G247- in 4 stages as follows:
  Note
An open-end spanner must not be used for loosening or tightening.
Special tools and workshop equipment required
  A23-10535
t  Socket, 27 mm -T40218-
t  Torque wrench
  W00-10779
StageTightening torque
1.Screw in by hand until it makes contact
2.60 Nm
3.Turn back by 180°
4.85 Nm

   

Checking injectors > < Injectors