Checking Fuel Pressure

Checking Fuel Pressure

Tools







Technical Values







Preliminary work
1. Fit protective covers to vehicle and in luggage compartment.







2. Remove engine cover.

Checking fuel pressure

INFORMATION:
- The battery voltage must not fall below 12 volts during the fuel pressure 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.

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.







2. Attach or mount a warning sign in a clearly visible position on the vehicle.

INFORMATION:
- Use the brass cap on the test connection of the fuel supply line only once as the sealing ring cannot be replaced. To avoid possible leaks, the cap must be replaced after removal.







3. Release metal cap on test connection at fuel collection pipe -Arrow- and screw it off by hand (a/f 13 mm).







4. Connecting cable 9559 must be connected using the pressure gauge 378a (union nut a/f 17).

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.







5. Tighten the knurled union nuts of the connecting cable by hand on the test connection of the fuel collection pipe -Arrow-. Collect emerging fuel with a cloth.

Procedure when the engine is standing still:
6. Connect the Porsche PIWIS Tester PIWIS Tester 9718 to the input socket in the vehicle using the adapter lead and switch on the ignition. Switch on the Tester and select the vehicle (option: Diagnostics).







7. 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 >>.







8. Once the individual control unit search for DME is complete, select the Drive links item, then select the fuel pump relay and activate it by pressing F8 - Start.

9. Read value on pressure gauge. Fuel pressure - engine not running: 3.8 bar ± 0.2 bar







10. Deactivate the fuel pump relay on the PIWIS Tester by pressing F8 - Stop. Then, press F11 << to return to the start screen and switch off the Tester.
11. Switch off the ignition and remove PIWIS Tester adapter lead in the vehicle.
12. Checking the engine at idle speed: connect the pressure gauge 378a as described above and start the engine. Switch off the engine after reading the fuel pressure. Fuel pressure - idle speed: 3.8 bar ± 0.2 bar

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.

13. Loosen the union nut on the connecting cable 9559 for the pressure gauge 378a on the test connection and remove special tool. Collect escaping fuel with a cloth.

INFORMATION:
- Use the brass cap on the test connection of the fuel supply line only once as the sealing ring cannot be replaced. To avoid possible leaks, the cap must be replaced after removal.

14. Position new closure cap on test connection and tighten (a/f 13 mm). - Tightening torque: 2.5 Nm (2 ftlb.) ± 0.5 Nm (± 0.5 ftlb.)

Subsequent work
1. Mount engine compartment cover.
2. Close convertible top.
3. Remove protective covers.

Subsequent work







1. Install engine cover.
2. Remove protective covers.