Checking Delivery Rate Of Electric Fuel Pump

Information 

• The battery voltage must not fall below 12.5 volts during the fuel delivery rate check. 

1. Attach or mount a warning sign in a clearly visible position on the vehicle.
   Fig 1: Example Of Warning Sign

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
2. Reduce fuel pump supply pressure. This procedure does not cause an entry to be made in the fault memory.
   1. 2.1. To do this, remove the cover of the fuse carrier in the left footwell and take out the fuse for the fuel pump - level D, fuse F1 (1st from left) -  .
   2. 2.2. Then start the engine. The engine runs for a short time and then stops.
   3. 2.3. Insert the fuse again and replace the cover.
3. PIWIS Tester II 9818  must be connected to the adapter line at the input socket in the vehicle and ignition must be switched on.
   1. 3.1. Switch off all loads, such as radio, air conditioning, etc. Switch on the Tester and select the relevant vehicle.
4. Select the menu DME  , Maintenance/repairs  and press [F12] to continue.
5. Select the menu Drain tank  and press [F12] to continue.
6. The following message is displayed.
   Fig 2: Drain Tank Message Screen Display

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
7. Have a Measurement Adapter 9705  , a fuel-resistant container, a measuring cup and a stopwatch to hand for measuring.
   Fig 3: Identifying Measurement Adapter (9705)

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
8. Open the retaining clip -1-  for the fuel lines on the underbody. To do this, unclip the locking lugs -arrow-  .
   Fig 4: Opening Retaining Clip On Fuel Lines

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
   WARNING: Highly inflammable or explosive materials

   • Danger of fire or explosion

   → Avoid contact with hot parts or sources of ignition.

   → Use suction to remove ignitable vapors.

   → Attach warning sign in a clearly visible position.

9. Disconnect rapid-action coupling on the fuel supply line -1-  by pressing in the locking lug and pulling off the coupling. Collect emerging residual fuel with a cloth.
   Fig 5: Identifying Rapid-Action Coupling On Fuel Pressure Line

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.
10. Connect the measurement adapter 9705  special tool to the fuel line using the rapid-action coupling. Make sure that the coupling is fitted correctly and securely (it must lock with an audible click).
    1. 10.1. Pull on the line to check that it is secure. 
       Fig 6: Connecting Measurement Adapter

       Courtesy of PORSCHE CARS NORTH AMERICA, INC.
11. Place the drainage hose after the pressure regulator into a petrol-resistant container. Make sure that the container does not tip over.
    Fig 7: Example Of Container

    Courtesy of PORSCHE CARS NORTH AMERICA, INC.
12. Have a stopwatch ready for the following measurement.
13. Start the Drain tank  routine by pressing [F8] and start the stopwatch at the same time.

    Measuring time: 60 seconds! 

    1. 13.1. Collect emerging fuel in a container you have to hand.
14. Press [F8] after 60 seconds to stop the routine.
15. Pour the collected fuel into the measuring cup and compare the quantity with the vehicle-specific values listed below.

    This gives the minimum pump rate. 

    1. 15.1. Carrera 2: 

       → Diameter: 2.80 l/min 

    2. 15.2. Carrera 4: 

       → Diameter: 2.75 l/min 

16. Remove measurement adapter 9705  and attach rapid-action coupling to fuel supply line. Collect escaping fuel. Make sure that the plug-in coupling is fitted correctly (must engage audibly) by pulling the line apart.
17. Switch off ignition, switch off the PIWIS Tester and disconnect adapter line to the vehicle.

    Information 

    • When the work is complete, check that all aids and foreign objects (e.g. cloths, tools) are removed from the engine compartment. 
18. Make sure there are no tools, foreign objects or aids left in the work area.