Fuel Pump: Testing and Inspection
Checking Quantity Delivered By Fuel Pump
Tools
Technical values
Preliminary work for quantity delivered by fuel pump
INFORMATION: The battery voltage must not fall below 12 volts during the fuel delivery rate check.
1. Check the battery charge state using a voltmeter or the Porsche PIWIS Tester. The battery voltage must not fall below 12 volts during the check.
2. Remove rear cover for underbody.
Checking quantity delivered by fuel pump
INFORMATION: The battery voltage must not fall below 12 volts during the fuel delivery rate check.
DANGER:
Risk of fire from escaping fuel.
- Danger of fatal injury and damage to property.
- Observe basic safety instructions when working on the fuel system.
- Secure working area.
1. Attach or mount a warning sign in a clearly visible position on the vehicle.
2. Reduce fuel pump supply pressure. 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 (No. 1 from left). Then start the engine for several seconds. This procedure does not cause an entry to be made in the fault memory. Insert the fuse again and replace the cover.
3. Connect the Porsche PIWIS Tester PIWIS Tester 9718 to the input socket in the vehicle using the adapter lead, switch on the ignition and switch off all loads, such as the radio and air conditioning. Switch on the Tester and select the vehicle (option: Diagnostics).
4. Run the individual control unit search for DME using the Porsche PIWIS Tester. To do this, select DME with the tracer pen and press F12 >>.
5. Select the Drive links item and then select the fuel pump relay.
6. Have a measurement adapter 9705, a fuel-resistant container, a measuring cup and a stopwatch to hand for measuring.
DANGER:
Risk of fire from escaping fuel.
- Danger of fatal injury and damage to property.
- Observe basic safety instructions when working on the fuel system.
- Secure working area.
7. Disconnect rapid-action coupling on the fuel supply line -1- by pressing in the locking lug and pulling off the coupling. Clean up emerging residual fuel with a cloth, for example.
8. Connect the measuring adapter 9705 special tool to the rapid-action coupling on the fuel line. Make sure that the plug-in coupling is fitted correctly (must engage audibly) by pulling the line apart.
9. Place the drainage hose after the pressure regulator into a petrol-resistant container. Make sure that the container does not tip over.
10. Activate the fuel pump relay on the Porsche PIWIS Tester. Press F8 - Start until fuel emerges at the drainage hose. Deactivate the fuel pump relay by pressing F8 - Stop and pour any leaked fuel from the container into a petrol-resistant container or into the fuel tank. Keep a stopwatch to hand for the following measurement.
11. Then, activate the fuel pump relay again by pressing F8 - Start and keep it going for 60 seconds. Start the stopwatch at the same time. Collect emerging fuel in an available container. Deactivate the fuel pump relay after 60 seconds by pressing F8 - Stop .
12. Pour the collected fuel into the measuring cup and compare the quantity with the vehicle-specific nominal values listed below.- Volume: 2.0 l/min ;- Volume: 2.3 l/min
13. 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.
14. Switch off ignition, switch off the Porsche PIWIS Tester and disconnect adapter lead to the vehicle.
Subsequent work for quantity delivered by fuel pump
1. Install rear cover for underbody.