skoda Workshop Repair Guides

Skoda Workshop Service and Repair Manuals

ABOUT US
Accelerator control > < Removing and installing the tandem pump

Fabia Mk2

Inspecting a tandem pump
Inspecting a tandem pump
Check feed pressure
Special tools and workshop equipment required
t  Pressure gauge appliance, e.g. -VAS 5187-
t  Pliers for spring strap clamps
t  Hose clamps -MP 7-602 (3094)-
Test conditions
l  The coolant temperature must be at least 85°C.
l  Unit injectors O.K.
l  Fuel filter and fuel line must not be blocked.
Work procedure
   
–  Release screw plug -arrow-.
  S20-0188
–  Connect pressure gauge appliance -VAS 5187- as shown.
–  Start engine and run in idle.
–  Note the pressure shown on the pressure gauge. Specified value: min. 0,35 MPa (3,5 bar).
–  Engine speed must increase to 4000 rpm.
–  Note the pressure shown on the pressure gauge. Specified value: min. 0.75 MPa (7.5 bar).
If the nominal value of min. 0.75 MPa (7.5 bar) is not reached:
–  Close return-flow line between tandem pump and fuel filter with hose clamp -MP 7-602 (3094)-.
–  Start engine and engine speed must increase to 4000 rpm.
–  Note the pressure shown on the pressure gauge. Specified value: min. 0.75 MPa (7.5 bar).
If the specified value is reached:
Pressure loss at the unit injectors.
–  Replace O-rings for unit injectors.
If the specified value is still not reached:
–  Replace tandem pump → Chapter.
  Note
After removing the pressure gauge appliance tighten the plug to 25 Nm. Always replace the gasket ring.
Check tightness (internally) of tandem pump
  Note
After re-installing an already used tandem pump e.g. after changing or repairing the cylinder head and/or after changing an engine without component parts, the tandem pump must be absolutely checked for internal tightness between fuel and oil part. In case of leakage fuel and oil can be mixed, which can cause an engine damage.
Special tools and workshop equipment required
t  Tester, e.g. -V.A.G 1687-
Work procedure
–  Disconnect the fuel intake hose (white marking) and the fuel return-flow hose (blue marking) from the tandem pump.
–  Close fuel return-flow connection at tandem pump with a dummy plug. Secure the dummy plug with a spring strap clamp.
Prepare tester e.g. -V.A.G 1687- as follows:
  S20-0221
–  Unscrew pressure control valve -2- fully and close the valves -3- and -4-.
–  Connect the testing device -5- with a commercially available connection for compressed air und a piece of fuel hose to the connection of the fuel feed line for the tandem pump. To secure use a spring strap clamp.
  Note
The rotary knob must be slightly pulled to the top in order to rotate the pressure control valve -2-.
–  Connect hose with compressed air -1- (pneumatic support) to tester e.g. -V.A.G 1687-.
  Note
If there is water in the inspection glass, drain water via the drain plug -6-.
–  Open valve -3-.
–  Set the pressure to 0,1 MPa (1,0 bar) with the pressure control valve -2-.
  WARNING
The maximum test pressure is 0.13 MPa (1.3 bar) and must not be exceeded.
  V21-0168
–  Open valve -4- and wait until the test circuit is filled. If necessary regulate the pressure to 0,1 MPa (1,0 bar).
–  Close the valve -3- to maintain the pressure and observe the drop in pressure over a period of 1 minute.
If no drop in pressure is detected, the tandem pump can be used again; in case of drop in pressure replace the tandem pump → Chapter.
  V21-0168

Accelerator control > < Removing and installing the tandem pump