Checking Fuel Pressure

Checking Fuel Pressure

Special Tools:

Test

1. Undo covering cap on test connection of fuel collection pipe and remove (width across flats 13 mm).

2. Connect pressure gauge (special tool P 378a) with connecting line (special tool 9559) and connect to test connection.





3. Actuate fuel pump, either

with Porsche System Tester 2:
The fuel pump can be actuated with the Porsche System Tester 2 or by bridging the fuel-pump relay.

or

via the fuel-pump relay without Tester:
Disconnect fuel-pump relay from the central electrical board and bridge contacts 30 and 87 (identified as 3 and 5 on the central electrical board) with a fused shop-made cable. The fuel pump must now operate or deliver fuel.





4. Nominal test values:

Stationary engine 3.8 ± 0.2 bar
Engine idling 3.3 ± 0.2 bar

NOTE: The seal or sealing ring in the brass closure cap is not exchangeable. It must therefore be used only once.

Tightening torque of the new brass closure cap 2.5 ± 0.5 Nm. (2.0 ± 0.5 ftlb.).