Volkswagen Golf / Golf GTI / Jetta. Manual — part 215

24-114

If the specification is not obtained:

- Check delivery rate of fuel pump:

Repair Manual, 2.8 Liter VR6 4V Engine

Mechanical, Engine Code(s): BDF; Repair Group
20

If the specification is obtained:

- Now check for leaks and holding pressure.

Watch 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 engine and run at idle.

When the fuel pump has built up the pressure
again:

- Switch ignition off after the pressure has built

up. Simultaneouslyclose pressure gauge VAG
1318 cut-off tap (handle across through- flow
direction -arrow-).

- Watch pressure drop on gauge again.

Components, checking

24-115

If the pressure does not drop:

- Check fuel pump non-return

valve:

Repair Manual, 2.8 Liter VR6 4V

Engine Mechanical, Engine Code(s):
BDF; Repair Group 20

If the pressure drops again:

- Open pressure gauge VAG 1318

shut-off tap (handle in direction of
flow -arrow-).

- Start engine and run at idle

speed.

If the pressure does not drop:

- Switch ignition off after pressure

has built-up. Simultaneously
clamp-off return supply hose (with
blue marking) -2-.

- Switch off ignition.

- Replace fuel pressure regulator

Page 24-28

, item 11 .

Components, checking

24-116

If the pressure drops again:

- Check line connections, O-rings on fuel rail and

fuel injectors for leaks.

- Check pressure gauge for leaks.

When the pressure gauge is removed after

completing the test:

- Remove fuse No. 28 from fuse holder again

before removing pressure gauge and place a
cloth around connections to be loosened.

Components, checking

24-117

Intake Manifold Change-Over
Valve -N156-, checking

The check need only be performed
when performance is poor.

The change-over from long to short
intake channels occurs at approx.
4400 rpm.

Special tools and equipment

VAG 1551 Scan tool (or VAG

1552) with VAG 1551/3 adapter
cable

Components, checking