Fuel Injectors, Removing and Installing Audi TT 8N

Removing

1. Remove intake manifold. Refer to «Intake manifold, removing and installing»(ref-276275-S24190931592008010300000) .

1. Disconnect fuel supply line -1- and fuel return line -2- by pressing release tabs.
2. Remove fuel rail together with injectors. Refer to «Fuel rail with injectors, disassembling and assembling»(ref-276275-S28859977752008010300000) . Fuel hoses remain connected.
3. Pull off retaining clip and remove injector.

Note. The fuel hoses must be disconnected before replacing the fuel rail.

Installing

Installation is performed in reverse order of removal. Note the following

1. Replace O-rings at all opened connections. (When replacing front O-ring, ensure that plastic cap is not removed from injector head. O-ring must be pulled off over plastic cap).
2. Lubricate O-rings with clean engine oil.
3. Make sure injectors are installed in correct position.
4. Make sure retaining clips are properly connected.

1. Position fuel rail with secured injectors on intake manifold and press evenly into place.

Tightening torque

Scheme 61

Special tools and equipment

1. Remote control V.A.G 1348/3 A with adapter cable V.A.G 1348/3-2
2. Adapter set V.A.G 1594 A
3. Injection rate tester V.A.G 1602
4. Test box V.A.G 1598/31

Requirements

1. Fuel pressure OK; checking. Refer to «Fuel system pressure, pressure regulator and holding pressure, checking»(ref-276275-S41753330212008010300000)

Work sequence

1. Remove intake manifold. Refer to «Intake manifold, removing and installing»(ref-276275-S24190931592008010300000) .
2. Remove fuel rail together with injectors. Refer to «Fuel rail with injectors, disassembling and assembling»(ref-276275-S28859977752008010300000) . Fuel hoses remain connected.

Checking for leaks

1. Open cover of fuse carrier and remove fuse 28 for Fuel pump -G6- (pre-supply pump).
2. Connect remote control V.A.G 1348/3 A with adapter cable V.A.G 1348/3-2 to contact 28a for fuel pump and to positive (+) battery terminal.
3. Connect battery cable Ground cable.
4. Activate remote control V.A.G 1348/3 A. Fuel pump must run.

1. Visually check fuel injectors for leaks.

When fuel pump is running, no more than 1 to 2 drops per minute should escape from any one injector.

If fuel loss is greater

1. Replace faulty injector. Refer to «Fuel injectors, removing and installing»(ref-276275-S25120213012008010300000) .

Checking injection quantity

1. Connect test box V.A.G 1598/31 to wiring harness for engine control module. Refer to «Wiring and component check on engine control module with test box VAG1598/31»(ref-276275-S10758802572008010300000) . Engine control module is not connected.
2. Use leads from adapter set V.A.G 1594 A to bridge contacts 1 and 65 at test box.

Scheme 62

1. Disconnect electrical connectors for fuel injectors by pressing retaining tab in direction of arrow.
2. Place a fuel injector in measuring glass of injection rate tester V.A.G 1602.

Scheme 63

1. Connect one contact of fuel injector to engine Ground using test lead and alligator clamp from adapter set V.A.G 1594 A.
2. Connect second contact of fuel injector to remote control V.A.G 1348/3 A with adapter cable V.A.G 1348/3-2.
3. Connect alligator clamp to positive (+) battery terminal.
4. Use leads from adapter set V.A.G 1594 A to bridge contacts 1 and 65 at test box.

1. If necessary, connect battery Ground cable.
2. Switch ignition on.

Fuel pump should run

1. Activate remote control VAG1348/3 A for 30 seconds.
2. Perform test for all injectors using a new glass each time.

Note. When checking the injection quantity, also check the spray pattern. The spray pattern should be the same for all the injectors.

1. Once all 6 injectors have been actuated, place measuring glasses on a level surface.

1. Specification: 128 to 140 ml for each injector

If measured values for one or more injectors are outside specification

1. Stop fuel pump (switch off ignition) and replace faulty injector. Refer to «Fuel injectors, removing and installing»(ref-276275-S25120213012008010300000) .

If measured values for all the injectors are outside specification

1. Check fuel pressure. Refer to «Fuel system pressure, pressure regulator and holding pressure, checking»(ref-276275-S41753330212008010300000) .
2. Install injectors with fuel rail. Refer to «Fuel rail with injectors, disassembling and assembling»(ref-276275-S28859977752008010300000) .