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Clean throttle valve control unit J338 > < Testing fuel injection rate

Fabia Mk2

Test fuel pressure regulator and holding pressure
Test fuel pressure regulator and holding pressure
Special tools and workshop equipment required
t  Pressure gauge appliance, e.g. -V.A.G 1318-
t  Adapter, e.g. -V.A.G 1318/9-
t  Adapter set, e.g. -V.A.G 1318/17-
t  Double connection piece -V.A.G 1318/23-
t  Remote control, e.g. -V.A.G 1348/3 A-
  Note
t  The fuel pressure regulator is a component part of the fuel filter and regulates the fuel pressure to approx 0.4 MPa (4 bar).
t  Observe safety measures → Chapter.
t  Observe rules for cleanliness → Chapter.
  WARNING
The fuel system is under pressure! Before opening the system lay cleaning cloths around the connection point. Reduce pressure by carefully releasing the connection point.
   
–  Separate the connector of the fuel feed line -3- and collect the fuel with flows out with a cloth.
  Note
Press together the securing ring in order to unlock the fuel line.
  S24-0602
–  Connect pressure gauge appliance, e. g. -V.A.G 1318- with adapter, e.g. -V.A.G 1318/9- and with adapter set, e. g. -V.A.G 1318/17- to fuel filter -1- and to fuel feed line -2-.
–  Open shut-off cock of the pressure measuring device.Lever points in direction of flow.
–  Venting air from the fuel system → Chapter.
–  Start engine and run in idle.
–  Measure fuel pressure.
Specified value: approx. 0.4 MPa (4.0 bar)
If the specification is not achieved
–  Switch off ignition.
–  Check the fuel flow rate of the fuel pump → Chapter.
–  If the fuel delivery unit is o.k., replace the fuel filter with integrated fuel pressure regulator.
If the specified value is reached
–  Switch off ignition.
–  Check for tightness and holding pressure (complete system). To this end observe the pressure drop on the pressure gauge. After 10 minutes there must still be at least 0.3 MPa (3 bar) pressure present.
If the holding pressure drops below 0.3 MPa (3 bar):
–  Start engine and run in idle.
  S24-0603
–  After the pressure has built up, switch ignition off. At the same time close the shut-off cock of the pressure measuring device (lever at right angles to direction of flow) -arrow-.
–  Observe pressure drop (engine side) on pressure gauge.
If the pressure still drops:
–  Check the line connections, the O-rings on the fuel rail and the injection valves for tightness.
–  Check pressure measuring device for tightness.
  Note
Before removing the pressure gauge appliance, place the cloth around the connection point.
If the pressure does not drop:
–  Check the line connections to the fuel tank and the non-return valve of the fuel delivery unit.
–  If the non-return valve is o.k., replace the fuel filter with integrated fuel pressure regulator → Chapter.
–  Venting air from the fuel system → Chapter.
  S24-0604

Clean throttle valve control unit J338 > < Testing fuel injection rate