Fuel Pressure Regulator: Testing and Inspection

Fuel Pressure Regulator and residual pressure, checking

^ Fuel pump delivery quantity OK

WARNING!
Fire Hazard! To prevent fuel spray when loosening connecting points, place rags around respective connection.




- Connect VAG 1318 pressure tester to measuring port using VAG 1318/11 and VAG 1318/23 adapters as shown.
- Open gauge valve (lever in direction of flow).
- Start engine and let idle.

If engine does not start:
- Remove Fuel Pump (FP) Relay (J17) from fuse/relay panel (position 12).




- Connect VAG 1348/3A remote switch between terminal -4- on fuse/relay plate and Battery Positive Voltage (B+) using VAG 1348/3-2 adapter cable.
- Operate remote switch and measure fuel pressure
^ Specified value: approx. 0.8-1.2 bar (11.6-17.4 psi)

If measured pressure value is too low:
- Replace upper section of Throttle Body.

If measured pressure value is too high:
- Check return line for blockage, replace upper section of Throttle Body if necessary.


Residual pressure, checking

- Switch ignition or remote switch OFF and check residual pressure.
^ At least 0.5 bar (7.25 psi) after 5 minutes

If residual pressure drops lower than spec, check the following:
^ Fuel line connections leaking
^ Fuel pump check valve NOT OK
^ Fuel Injector O-rings leaking
^ Fuel Injector leaking
^ Fuel pressure regulator NOT OK

Note: The upper section of the Throttle Body and the fuel pressure regulator are matched parts. If the pressure regulator is replaced, also replace the upper section of the Throttle Body.