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Checking fuel flow rate with pressure gaugeV.A.G 1318 > < Checking holding pressure with pressure gaugeV.A.G 1318

Octavia Mk2

Checking holding pressure with pressure gaugeVAS 6550
Checking holding pressure with pressure gauge -VAS 6550-
   
l  Fuel pressure O.K. and pressure gauge -VAS 6550- connected in the engine compartment → Chapter.
  Note
t  Safety precautions when working on the fuel supply system → Chapter.
t  Rules of cleanliness when working on the fuel supply system → Chapter.
–  Switch the ignition on and off so often until the fuel pressure on the pressure gauge does no longer rise.
–  Read off fuel pressure on the pressure gauge.
l  Specified value: 0.4 ... 0.7 MPa (4 ... 7.0 bar)
–  Observe pressure drop at pressure gauge.
l  The pressure must not drop below 0.3 MPa (3.0 bar) after 10 minutes.
If the pressure again drops:
–  Switch the ignition on and off so often until the fuel pressure on the pressure gauge does no longer rise.
  N20-10628
–  Immediately close the shut-off cock -B- of the pressure gauge after the pressure has built up. The lever points at right angles in the direction of flow.
Now the pressure does no longer drop:
  Note
Search for leakage on the engine side. Repeat the holding pressure test. This time, close the shut-off cock -A- in order to determine if a leak is indeed present on the engine side.
–  Check the low-pressure line to the high pressure pump for tightness.
If no fault is found:
–  Replace high pressure pump → Chapter.
If the pressure again drops:
Search for leakage on the fuel tank side, to do so proceed in the following manner:
–  Check the fuel line to the fuel filter for tightness.
If the fuel line is not found to be faulty:
–  Check the pressure holding valve in the fuel delivery unit. To do so proceed in the following manner:
  S20-0349
–  Disconnect fuel feed line -arrow- at fuel filter.
  N20-10629
–  Connect the pressure gauge -VAS 6550- with the adapter -VAS 6550/1- and -VAS 6550/2- between the fuel filter and the fuel feed line.
–  Make sure that the discharge cock is closed and the shut-off cocks are opened.
–  Switch the ignition on and off so often until the fuel pressure on the pressure gauge does no longer rise.
–  Read off fuel pressure on the pressure gauge.
l  Specified value: 0,58 ... 0,70 MPa (5,8 ... 7.0 bar)
  N20-10630
–  After the pressure has built up, close the shut-off cock -A-.
–  Observe pressure drop at pressure gauge.
l  The pressure must not drop below 0.3 MPa (3.0 bar) after 10 minutes.
If the pressure still drops:
–  Non-return valve in the fuel pump faulty, replace fuel delivery unit:
t  Fabia II, Roomster → Chapter.
t  Octavia II, Yeti (version l.) → Chapter.
t  Yeti (version II.) → Chapter.
If the pressure does not drop:
–  Pressure limiting valve in the fuel filter defective, replace the fuel filter.
  S20-0349

Checking fuel flow rate with pressure gaugeV.A.G 1318 > < Checking holding pressure with pressure gaugeV.A.G 1318