SEAT Workshop Service and Repair Manuals

The fuel pressure regulator regulates the fuel pressure depending on intake manifold pressure.

The specification for the check is dependent upon the working pressure of the fuel pump. This is

    approx. 3.0 bar

Special tools, workshop equipment, test and measuring appliances and aux. items required

• ◆ V.A.G 1318 Pressure gauge
• ◆ 1318/7 Adapter
• ◆ 1318/13 Adapter
• ◆ 1318/17 Adapter
• ◆ V.A.G 1921 Pliers for spring-type hose clips

Test conditions

• ● Fuel pump delivery rate OK, checking:

=> Rep. Gr. 20; Removing and installing parts of fuel system; checking fuel pump

Test sequence

• ‒ Pull fuel pump fuse No. 14 for fuel pump relay out of fuse holder.

• ‒ → Pull fuel supply hose -1- (black) off fuel distributor and catch escaping fuel with a rag.

• ‒ → Connect K-Jetronic pressure tester V.A.G 1318 using adapters V.A.G 1318/17, V.A.G 1318/13 and V.A.G 1318/7 to fuel supply hose and to fuel rail.
• ‒ Open shut-off tap on pressure gauge. The handle points in direction of flow.
• ‒ Insert fuel pump relay fuse No. 14 into fuse holder.
• ‒ Start the engine and run at idling speed.
• ‒ Measure fuel pressure.
      Specification: Approx. 2.5 bar

• ‒ → Pull the vacuum hose off fuel pressure regulator -arrow- . The fuel pressure must increase to
      approx. 3.0 bar.

If the specification is not obtained:

• ‒ Check quantity supplied by fuel pump.

=> Rep. Gr. 20; Removing and installing parts of fuel system; checking fuel pump

If the specification is obtained:

• ‒ Switch off ignition.
• ‒ Check for leaks and holding pressure by observing pressure drop on gauge. After 10 minutes there must be
      a residual pressure of
  at least 2.0 bar.

If the holding pressure drops below 2 bar:

• ‒ Start the engine and run at idling speed.

When the fuel pump has built-up the pressure again:

• ‒ → Switch ignition off after the pressure has built-up. At the same time close pressure measured device cut-off tap (handle cross through-flow direction -arrow-).
• ‒ Watch pressure drop on gauge.

If the pressure does not drop:

• ‒ Check fuel pump non-return valve:

=> Rep. Gr. 20; Removing and installing parts of fuel system; checking fuel pump

If the pressure drops again:

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

If no leaks can be found:

• ‒ Switch off ignition.
• ‒ Renew fuel pressure regulator.

When the pressure gauge is removed after completing the test:

• ‒ Remove fuse No. 14 again and wrap a rag around the adapter which is to be removed and remove pressure tester.