Volkswagen Workshop Service and Repair Manuals

Special tools, workshop equipment, test and measuring appliances and auxiliary items required

• ◆ 3217 Ring nut spanner
• ◆ V.A.G 1318 K-Jetronic tester
• ◆ V.A.G 1318/1 Adapter
• ◆ V.A.G 1318/10 Adapter hose
• ◆ V.A.G 1318/11 Adapter

Special tools, workshop equipment, test and measuring appliances and auxiliary items required

• ◆ V.A.G 1526 A Hand multimeter
• ◆ V.A.G 1527 B Diode test lamp
• ◆ V.A.G 1594 A Adapter set
• ◆ V.A.G 1715 Multimeter
• ◆ V.A.G 1348/3 Remote control
• ◆ V.A.G 1348/3-2 Adapter cable

• ● Battery voltage at least 11 V.
• ● Fuse 18 must be OK.

• ‒ Switch on ignition.

Fuel pump must be heard to run briefly.

If the fuel pump does not run:

• ‒ Switch off ignition.
• ‒ Pull off cover in front of relay plate.
• ‒ → Pull the fuel pump relay (J17) out of relay plate (relay position 12).

Notes:

• ◆ If tools are necessary to pull relays or control units out of the relay plate, first disconnect battery earth strap.
• ◆ Before disconnecting battery earth strap obtain code for radios with anti-theft coding.

• ‒ Connect remote control V.A.G 1348/3A with adapter cable V.A.G 1348/3-2 to contact 4 and battery positive (+).
• ‒ Operate remote control.

Fuel pump runs:

• ‒ Locate and eliminate open circuit using current flow diagram:

=> Current flow diagrams, Electrical fault finding and Fitting locations

• ‒ Check activation of fuel pump relay:
• ‒ Renew fuel pump relay if necessary.

Fuel pump does not run:

• ‒ Remove cover in luggage boot floor.
• ‒ Pull 4-pin connector off fuel tank flange.

• ‒ → Connect diode test lamp V.A.G 1527 with aux. cables from V.A.G 1594 to the outer contacts of the connector.
• ‒ Operate remote control.
       LED must light up

LED does not light up:

• ‒ Locate and eliminate open circuit using current flow diagram:

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

LED lights up (voltage supply OK.):

• ‒ Unscrew union nut with 3217.
• ‒ Check that the electrical wires between flange and fuel pump are connected.

If not open circuit can be found:

• ‒ Renewing fuel delivery unit
  =>Page 20-23 , Removing and installing fuel delivery unit.

Checking delivery rate

The specification for this test is dependent upon fuel pump pressure.
     ▸07.95 approx. 4 bar
     08.95 ▸ approx. 3 bar

• ● Voltage supply OK.

• ● Remote control V.A.G 1348/3A connected.

• ‒ Remove fuel tank cap.
• ‒ → Pull fuel supply hose -1- off fuel manifold.

Note:

To prevent fuel spray when loosening connections wrap a cloth around the connection.

• ‒ Connect pressure gauge V.A.G 1318 with adapter 1318/10 to the fuel supply hose -1-.
• ‒ Push hose V.A.G 1318/1 on pressure gauge adapter V.A.G 1318/11 and hold in measuring container.
• ‒ Open fuel gauge cut-off tap (lever in through-flow direction - position -A-).

Vehicles ▸07.95

• ‒ Operate remote control V.A.G 1348/3A and slowly close cut-off tap, until the gauge shows
       4 bar
  leave cut-off tap in this position.

• ‒ Empty measuring container.
• ‒ Operate remote control for
       30 seconds.
• ‒ → Compare amount of fuel delivered with specification.

     *)     Minimum delivery cm3/30 seconds

     **)     Voltage at fuel pump with engine stopped and pump running (approx. 2 volts less than battery voltage).

Vehicles 08.95 ▸

• ‒ Operate remote control V.A.G 1348/3A and slowly close cut-off tap, until pressure gauge shows
       3 bar.
  From this point on do not move position of cut-off tap.
• ‒ Empty the measuring container.
• ‒ Connect multimeter to vehicle battery to measure voltage using auxiliary cables from V.A.G 1594.
• ‒ Operate remote control for
       30 seconds.

• ‒ → Compare the quantity of fuel delivered with specification.

     *)     Minimum delivery cm3/30 seconds

     **)     Voltage at fuel pump with engine stopped 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 then this will equate to a minimum delivery of 550 cm3/30 s.

For all vehicles:

If the minimum delivery rate is not attained:

• ‒ Check the fuel pipes for possible restrictions (kinks) or blockages.

• ‒ → Pull the supply hose -1- off inlet to fuel filter.
• ‒ Connect the pressure gauge V.A.G 1318 to hose with adapter 1318/10.
• ‒ Repeat delivery rate check.

If the minimum delivery rate is now attained:

• ‒ Replace the fuel filter.

If the minimum delivery rate is again not attained:

• ‒ Remove the fuel delivery unit and check the strainer filter for soiling.

Only when up to now no fault has been detected:

• ‒ Replace the fuel delivery unit.

If the delivery rate has been attained but nevertheless you suspect a fuel supply system fault (e.g. intermittent failure of fuel supply system):

• ‒ Check the current draw of the fuel pump as follows:
• ‒ Reconnect all disconnected fuel pipes.

• ‒ → Connect the multimeter V.A.G 1715 using the current clamp to the red/yellow wire from wiring loom.
• ‒ Start the engine and run at idling speed.
• ‒ Measure the current draw of the fuel pump.
       Specification: max. 8 amps.

Note:

If the fuel system malfunction is intermittent, you can perform the check during a test drive with the help of a 2nd person.

If the current draw is exceeded:

• ‒ Replace the fuel delivery unit.

Checking fuel pump non-return valve

• ● Remote control V.A.G 1348/3A connected
• ● Pressure gauge V.A.G 1318 connected

Note:

With this check the fuel supply pipe connections from the fuel delivery unit to the point at which the pressure gauge V.A.G 1318 is connected will be checked for leaks at the same time.

• ‒ → Close pressure gauge shut-off tap (lever at right angles to throughflow direction - position -B-).
• ‒ Operate remote control at short intervals, until a pressure of
       ▸07.95 approx. 4 bar
       08.95 ▸approx. 3 bar
  has built-up.
• ‒ If pressure builds up too high, lower excess pressure by carefully opening the cut-off tap.

• ‒ Watch pressure drop. After 10 minutes the pressure must not drop below
       ▸07.95 approx. 3 bar
       08.95 ▸approx. 2.2 bar
  If necessary check pipe connections for leaks and/or renew fuel delivery unit
  =>Page 20-23 , Removing and installing fuel delivery unit