Volkswagen Workshop Service and Repair Manuals

Special tools, testers and auxiliary items

• ◆ Pressure tester V.A.G 1318
• ◆ Adapter 1318/10

Test conditions

• ● Fuel pump delivery rate OK, checking:

=> Repair group 20; Removing and installing parts of the fuel supply system; Checking fuel pump

Test sequence

• ‒ → Pull sealing cap -1- off gauge connecting point -2-. To do this release sealing cap by pressing on the sides -arrows-.
• ‒ Connect pressure gauge V.A.G 1318 with adapter 1318/10 to measuring point.

• ‒ Start engine and run at idling speed.
• ‒ Check fuel pressure.
       Specification: Approx. 2.5 bar

• ‒ → Pull vacuum hose -1- off connection -2-. The fuel pressure must increase to
       Approx. 3.0 bar.
• ‒ Switch off ignition.
• ‒ Check for leaks and holding pressure by watching pressure drop on gauge. After 10 minutes there must be
       a residual pressure of
  at least 2 bar.

If the holding pressure drops below 2 bar:

• ‒ Start engine and run at idling speed.
• ‒ After the pressure has built up switch off ignition and at the same time clamp-off the return pipe -with blue arrow- on fuel manifold.
• ‒ Watch pressure drop on gauge.

If the pressure does not drop:

• ‒ Renew fuel pressure regulator.

If the pressure drops again:

• ‒ Check fuel pump non-return valve.

=> Repair group 20; Removing and installing parts of the fuel supply system; Checking fuel pump

• ‒ Check pipe connections, O rings on fuel manifold and injectors for leaks.

Note:

Before removing the pressure gauge release fuel pressure by opening the cut-off tap. When doing this hold a container over the connection.