Fuel Pump: Testing and Inspection

Checking Quantity Delivered By Fuel Pump

WARNING: Observe the general safety instructions when working on the fuel system and when handling petrol and other fuels.
Attach or mount a warning notice on the vehicle in a clearly visible position.
Only carry out checking when engine is standing still.
Ensure good ventilation in the work area (e.g., open window, switch on exhauster).

Secure vehicle with warning sign:










NOTE: The battery voltage may not fall below 12 volts during the fuel pressure check.

1. Check the charge state of the battery, e.g. using a voltmeter or the Porsche System Tester PST 2. The battery voltage must not fall below 12 volts during the check.
2. Connect the Porsche Tester PST 2 in the vehicle, switch on the ignition and switch off all loads, such as the radio and air conditioning.
3. Remove the rear and middle underside panels. To remove the rear panel, the left side panel must also be loosened.
4. Loosen the rapid-action coupling on the fuel return line -arrow- ; to do this, press in the locking lug and pull off the coupling. Collect emerging residual fuel with a cloth, for example.







5. Insert receptacle into the open end of the hose for the special tool connection hose 9507 and connect with the rapid-action coupling of the fuel return line. Be sure that the coupling is fitted correctly (must engage audibly) by pulling the line apart.







6. Put the open end of the hose in a petrol-resistant canister. Keep a stopwatch at hand for the following measurement.
7. Activate the fuel pump relay using the Porsche System Tester PST 2. To do this, select the line drive links in the DME control unit individual search and then select fuel pump relay. Activate by pressing F8. After 30 seconds, deactivate the relay again by pressing F8.







8. Transfer the collected fuel into a suitable measuring cup.
Target value for supplied fuel quantity:
- in 30 seconds, at least 1.25 litres

9. Remove the receptacle with hose and insert the rapid-action coupling onto the fuel return line. Be sure that the coupling is fitted correctly (must engage audibly) by pulling the line apart.
10. Install underside panels.
11. Switch off ignition, switch off Porsche System Tester and disconnect.