Fuel Pressure: Testing and Inspection

Checking Fuel Pressure

Tools












Tools and materials

Special tools







Information

Test conditions
- The battery voltage must not be < 12 volts.
- If an insufficient delivery rate is determined in the delivery rate test, the measurement on the second scavenging valve of the fuel gallery will be repeated.
- Fuel system parts must not get dirty.

Checking fuel pressure
1. Pull the cover of the throttle body up and off.







2. Unscrew cap on the front right of the fuel gallery.
3. Connect connection line 9559 to the pressure gauge p378. Screw the other end onto the fuel gallery.







4. Switch on the ignition and start the engine. Read off fuel pressure on pressure gauge. The value must be 4.0 ± 0.2 bar at idle speed.







DANGER:
Danger of fire due to incorrect or faulty scavenging valves.
- Replace scavenging valves after removing.
- Only use the special, Porsche-approved valves in the fuel gallery.
- Do not replace scavenging valves by tyre valves.
- It is essential that the plastic cap is also replaced.

NOTE: The steady-state pressure must be greater than 2.0 bar after 1 hour.

5. Unscrew connection line and close the fuel gallery with a new plastic cap.







6. Press the 4 rubber elements in the cover onto the 4 ball head supports. The mounts must be felt to engage.