Page 121 of 136
Downloaded from www.Manualslib.com manuals search engine Fuel Supply System20
Edition 08.96
Removing and installing fuel delivery unit
Pay attention to safety precautions ⇒
page 20-4.
Pay attention to rules for cleanliness ⇒ page
20-4. Special tools, testers and aids required♦ Wrench for union nut MP 1-227
Removing
- If car is fitted with a coded radio set, deter- mine coding, if necessary.
- Switch off ignition (if not already off) and dis- connect earth strap at the battery.
- Unbolt cover (below the rear seat).
- Disconnect feed and return flow pipes from the flange of the fuel delivery unit (press release buttons).
- Release 4-pin connector from the flange at the fuel tank and unplug.
- Use wrench MP 1-227 to unscrew union nut.
- Pull fuel delivery unit and seal out of the
opening of the fuel tank.
Note:
If the delivery unit is still filled with fuel, emptybefore replacing.
Installing Installation is performed in the reverse order; pay attention to the following points:
Notes:
♦When inserting the fuel delivery unit, ensure
that the fuel gauge sender is not bent.
♦Moisten seal of the flange with fuel beforeinstalling.
♦Ensure the fuel hoses are tightly connected.
Page 123 of 136
Downloaded from www.Manualslib.com manuals search engine Fuel Supply System20
Edition 08.96
Removing
- If car is fitted with a coded radio set, pay attention to coding; determine if necessary.
- Switch off ignition (if not already off), and disconnect earth strap at the battery.
- Empty fuel tank with fuel extraction unit (e.g. V.A.G 1433 A).
- Remove rear suspension: ⇒ Running Gear; Repair Group 42; Servicing rear suspension; Removing and installing rear suspension.
- Unbolt cover (below the rear seat).
- Release 4-pin connector from the flange at fuel tank and unplug.
- Open fuel filler flap and lever out tensioning ring in rubber bowl (around filler neck).
- Push rubber bowl through to the inside.
- Remove rear right wheelhouse liner.
- Unscrew fuel filler neck below the wheel- house liner.
- Remove cover below the fuel tank -arrows-
(if fitted).
- Disconnect return flow pipe -2- (blue), feed
pipe -1- (black) and breather pipe -3- (white) at the front right of the fuel tank (press release buttons).
- Place engine/gearbox jack (e.g. V.A.G 1383 A) below the fuel tank to support it.
Page 124 of 136
Downloaded from www.Manualslib.com manuals search engine
20Fuel Supply System
Edition 08.96
- Detach screw connections -arrow- at the
front left and at the retaining straps.
- Lower fuel tank. Installing Installation is performed in the reverse order; pay attention to the following points:
- Connect fuel pipes to the flange of the fuel
delivery unit:
Blue return flow pipe -1- to connection marked with -R-.
Black feed pipe -2- to connection marked with -V-.
Connecting remote control
Special tools, testers and aids required Remote control V.A.G 1348/3A with adapter
cable V.A.G 1348/3-2
Procedure
- Open cover of the fuse box on the left-hand side of the dash panel.
- Remove fuse 28 at the fuse carrier (left-hand row, 5th large fuse form the top).
- Connect remote control V.A.G 1348/3A with
adapter cable V.A.G 1348/3-2 to the fuse base of fuse 28 -arrow-.
- Connect clamp to car battery (+).
Page 125 of 136
Downloaded from www.Manualslib.com manuals search engine Fuel Supply System20
Edition 08.96
Testing fuel pump
Special tools, testers and aids required
Hand-held multimeter (e.g. V.A.G 1526)
Wrench for union nut (e.g. MP 1-227)
Adapter cable set (e.g. V.A.G 1594)
Current flow diagram
Test conditions
Holding pressure o.k.; testing:
1.8 ltr./92 kW Engine, Motronic Fuel Injection and Ignition System; Repair Group 24;
Testing fuel pressure regulator and holding pressure
Battery voltage at least 12 V
Fuse 28 o.k.
Fuse filter o.k.
Test procedure
- Switch on ignition. The fuel pump should be heard to operate. (A second mechanic may be required if there is a high level of surrounding noise) If the fuel pump does not run:
- Switch off ignition.
- Connect remote control V.A.G 1348/3A with adapter cable V.A.G 1348/3-2 page 20-8.
- Operate remote control.If the fuel pump runs:
Test fuel pump relay: 1.8 ltr./92 kW Engine, Motronic Fuel Injection and Ignition System; Repair Group 24; Servicing Motronic fuel injection system; testing fuel pump relay and actuation
Page 126 of 136
Downloaded from www.Manualslib.com manuals search engine
20Fuel Supply System
Edition 08.96
If the fuel pump does not run:
- Unbolt cover (below the rear seat).
- Release 4-pin connector form the flange at
the fuel tank and unplug.
- Connect hand-held multimeter (e.g. V.A.G
1526) with auxiliary cables (e.g. from V.A.G
1594) to the outer contacts of the connector.
- Operate remote control. Specification: about battery voltage
If the specification is not achieved:
- Determine open circuit in the wiring on the basis of the current flow diagram and rectify:
⇒ Current Flow Diagrams, Electrical Fault Finding and Fitting Locations binder
If the specification is achieved:
- Use MP 1-227 to unscrew union nut.
- Check whether the electric cables between flange and fuel pump are connected and test
for continuity.
If no open circuit in the wiring can be found:
Fuel pump faulty.
- Replace fuel delivery unit ⇒ page 20-5.
Testing delivery of the fuel pump
Special tools, testers and aids required♦ Adapter V.A.G 1318/17
♦ Measuring vessel
Test conditions
Battery voltage at least 12 V
Voltage supply o.k.
Fuel filter o.k.
Page 127 of 136
Downloaded from www.Manualslib.com manuals search engine Fuel Supply System20
Edition 08.96
Test procedure
- Switch off ignition.
- Connect remote control V.A.G 1348/3A with
adapter cable V.A.G 1348/3-2 ⇒ page 20-8.
- Remove cap from the fuel filler neck.
Important! Fuel system is pressurised! Place cleaning ragsaround the connection point before opening the
system. Then, release pressure by carefullyloosening the connection point.
- Disconnect fuel return flow pipe -2- (press
release buttons).
- Connect auxiliary hose to adapter V.A.G 1318/17 and fit onto the fuel return flow pipe of the engine and hold in a measuring vessel.
- Operate remote control for 15 seconds (press button and hold).
- Compare quantity of fuel supplied with spe-
cification.
*)Minimum delivery cm3/15 s
**)Voltage at fuel pump when engine switched
off and pump running (about 2 V less than battery voltage).
