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Fuel tank (Petrol) > < Fuel tank (Autogas)

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Testing check valve of fuel pump
Testing check valve of fuel pump
–  Remove the rear right seat → Rep. gr.72
   
–  Remove cover from fuel delivery unit.
  A20-1206
–  First check if the connector -arrow- has been inserted correctly; pull on the connector without pressing the locking mechanism. Malfunctions may arise when the connector has not been inserted correctly.
–  Extract the connector -arrow- from the fuel delivery unit.
–  Check the contact on the plug connector and the fuel supply unit for damage.
  N20-10623
–  Connect the adapter for the DSO measuring/oscilloscope module (5 contacts) -VAS 5565-to the connector in the fuel supply unit.
–  Connect the remote control for V.A.G 1348 -V.A.G 1348/3A- to the measurement adapter / DSO (5 poles) -VAS 5565- and to battery positive (+).
  WARNING
Fuel supply line is pressurised. Wear safety goggles and appropriate clothing to avoid injury and contact with skin. Before loosening hose connections, wrap a cloth around the connection. Then eliminate the pressure by carefully separating the pipe.
  N20-10422
–  Remove the supply hose -arrow- from the fuel filter inlet.
  N20-10629
–  Connect fuel supply pipe to pressure tester -VAS 6550-, using adapter -VAS 6550/1-. Guide the adapter -VAS 6550/2- into a measuring beaker.
–  Close the shut-off valve -A- of the pressure gauge equipment -VAS 6550- (lever arm transverse to direction of flow).
–  Operate the remote control for short periods until an overpressure of approx. 4 bar has been established.
  WARNING
Fuel may splash when opening the shut-off valve. Wear safety goggles and appropriate clothing to avoid injury and contact with skin. Place a container under the free coupling of the pressure gauge.
–  If pressure builds up too high, lower excess pressure by carefully opening the shut-off tap.
–  Check the pressure drop on the pressure tester. After 10 minutes the pressure must not drop below 3 bar.
If the pressure drops further:
–  Check pipe connections for leaks.
If no fault in lines is detected:
–  The fuel pump is defective which is why the fuel delivery unit should be renewed.
  N20-10632

Fuel tank (Petrol) > < Fuel tank (Autogas)