Test Point 28 - Fuel Pressure

TEST POINT 28 - Fuel pressure

Possible Causes, Elimination, Remarks
The left-hand fuel collection pipe has a test connection at cyl. no. 3.
- Unscrew the cap nut of the test connection.

CAUTION: The inserted ball seat could fall out!

- Connect pressure gauge P 378 or VW 1318 to the test connection. Start engine.

Test pressure 3.3 ±O.2 bar (48 ±3 psi) @ Idle speed

In case of hot starting problems:
- Check with engine stopped and fuel pump running. For the test, remove fuel pump relay and jumper terminal 87b and terminal 30.

Test pressure 3.8 ±O.2 bar (55 ±3 psi)

- Switch off fuel pump. Read off pressure on pressure gauge (nominal 3.8 O.2 bar).

Max. permissible pressure drop with warm engine: 0.5 bar (7.25 psi) in 30 minutes.

- If the pressure drops below the specified value, proceed as described below:




- Build up pressure again by switching on the fuel pump briefly. Remove return pipe from pressure regulator (fuel pump must not be switched on).