Fuel Injector: Testing and Inspection
Fuel Injectors, Checking Injection Quantity, Spray Pattern and Seal
Special tools, testers and auxiliary items required
• Remote control (V.A.G 1348/3 A) with adapter cable (V.A.G 1348/3-2)
• Connector test kit (V.A.G 1594 C) or (V.A.G 1594 A)
• Adapter cable (V.A.G 1598/31) (test box)
• Injector quantity testing device (V.A.G 1602)
Test Conditions
• Fuel pressure OK, checking => [ System Pressure, Fuel Pressure Regulator and Residual Pressure, Checking ] Testing and Inspection.
Test Sequence
- Remove intake manifold => [ Intake Manifold ] Intake Manifold.
- Remove fuel rail with fuel injectors installed => [ Fuel Rail with Fuel Injectors ] Overhaul. Fuel line remains connected.
Checking for Leaks
- Open E-Box cover in engine compartment and pull out Fuse 33 (on fuse panel B) SB33.
- Connect remote control (V.A.G 1348/3 A) with adapter cable (V.A.G 1348/3-2) to terminal of Fuel Pump (FP) fuse and to battery plus (+).
- Connect battery Ground (GND) cable.
- Press switch on remote control connection (V.A.G 1348/3 A).
• Fuel Pump (FP) must run.
- Check seal of fuel injectors via visual inspection.
• With Fuel Pump (FP) running, only 1 to 2 drops per minute should escape from each fuel injector.
If fuel loss is greater:
- Replace faulty fuel injector => [ Fuel Injectors ] Removal and Replacement.
- Re-insert Fuse 33 (on fuse panel B) SB33 in E-Box in engine compartment.
Injection Quantity, Checking
- Connect adapter cable (V.A.G 1598/31) (test box) to wiring harness to Engine Control Module (ECM) => [ Wiring and Components, Checking with 121-Point Adapter Cable on ECM ] Wiring and Components, Checking With 121-Point Adapter Cable on ECM. The Engine Control Module (ECM) is not connected.
- Bridge terminals 1 and 65 at test box using wires from adapter test kit (V.A.G 1594 C).
- Disconnect electrical harness connectors for fuel injectors.
- Place a fuel injector into a graduated measuring glass of injection quantity test device (V.A.G 1602).
- Connect one terminal of fuel injector to plus wire and an alligator clip from connector test kit (V.A.G 1594 C) to engine Ground (GND).
- Connect second terminal of fuel injector to remote control (V.A.G 1348/3 A) using adapter cable (V.A.G 1348/3-2).
- Connect alligator clip to battery plus (+).
- Bridge terminals 1 and 65 at test box using wires from adapter test kit (V.A.G 1594 C).
- Connect battery Ground (GND) cable if necessary.
- Switch ignition on.
• Fuel Pump (FP) must run.
- Press switch on remote control connection (V.A.G 1348/3 A) for 30 seconds.
- Perform measurement at all fuel injectors using a new measuring glass for each.
• Also check spray pattern when testing injection quantity. Spray pattern must be the same for all injectors.
- After all 6 fuel injectors have been activated, place measuring glasses on an even surface.
• Specified value of injection quantity for each fuel injector: 128 to 4.73 fl oz
If measured value of one or more fuel injectors is not within tolerance range:
- Shut off Fuel Pump (FP) (switch off ignition) and replace malfunctioning fuel injector => [ Fuel Injectors ] Removal and Replacement.
If measured values of all fuel injectors are outside specified range:
- Check fuel pressure => [ System Pressure, Fuel Pressure Regulator and Residual Pressure, Checking ] Testing and Inspection.
- Install fuel injectors together with fuel rail => [ Installation is in reverse order of removal,
noting the following: ] Removal and Replacement.
- Install intake manifold => [ Intake Manifold ] Intake Manifold.