Volkswagen Golf / Golf GTI / Jetta. Manual — part 77

20-31

Checking delivery rate

Test conditions

Voltage supply OK.

Remote control VAG 1348/3A

connected.

Test sequence

- Remove filler cap from fuel tank

filler neck.

Note:

Press buttons on hose couplings to
do so.

WARNING!

Fuel supply lines are under
pressure! Before removing from
hose connections wrap a cloth
around the connection. Then
release pressure by carefully
pulling hose off connection.

- Disconnect supply hose -3- (with

white marking) and collect fuel
that may leak out with a cloth.

Components of fuel supply system, servicing

20-32

The quantity of fuel delivered by the
fuel pump depends on the battery
voltage.

- Connect pressure gauge VAG

1318 to fuel supply pipe using
adapter VAG 1318/23 and VAG
1318/17.

- Push hose adapter VAG 1318/16

onto adapter VAG 1318/11 on
pressure gauge and hold hose in
a measuring container.

- Open shut-off tap on pressure

gauge. Lever then points in flow
direction -A-.

- Operate remote control VAG

1348/3A. Close shut-off tap
slowly, until pressure gauge
shows 3 bar. From now on do not
alter setting of shut-off tap.

- Empty measuring container.

- Connect multimeter to vehicle

battery using adapter cables from
VAG 1594 A.

- Operate remote control for 30

seconds and measure battery
voltage.

Components of fuel supply system, servicing

20-33

*)

Minimum delivery cm

3

/30 seconds

**)

Voltage at fuel pump with engine

not running and pump running
(approx. 2 volts less than battery
voltage).

Example:

During the test, a voltage of 12.2
volts is measured at the battery. As
the voltage at the pump is approx. 2
volts less than the battery voltage,
the result is a minimum delivery of
200 cm

3

/30 seconds.

If the minimum delivery rate is not
attained:

- Compare quantity of fuel

delivered with nominal value.

- Check fuel pipes for possible

restrictions (kinks) or blockages.

Note:

Press buttons on hose couplings to
disconnect.

- Disconnect fuel line -1- from input

side of fuel filter.

- Connect pressure gauge VAG

1318 to hose using adapter
1318/17.

- Repeat delivery rate test.

Components of fuel supply system, servicing

20-34

If the minimum delivery rate is now attained:

- Replace fuel filter.

If the minimum delivery rate is again not

attained:

- Remove fuel delivery unit and check strainer

filter for soiling.

Only if no faults have been detected up to now:

- Fuel pump faulty, replace fuel delivery unit

Page 20-15

, Removing and installing fuel

delivery unit.

If the delivery rate has been attained but a fuel

supply system fault is still suspected (e.g.
intermittent failure of fuel supply system):

- Check current draw of fuel pump as follows:

- Reconnect all disconnected fuel lines.

Components of fuel supply system, servicing