With Generic Scan Tool
Checking Fuel Injectors For Injection Quantity And Proper Seal
Recommended special tools and equipment
- VAG1348/3A remote control with VAG1348/3-2 adapter cable
- V.A.G 1602 tester for quantity of injected fuel
Without illustration:
- VAG1594A connector test kit
Test requirement
- Fuel pressure must be OK, check, fuel pressure regulator and retaining pressure, checking. Fuel Pressure Regulator and Residual Pressure, Checking
Test sequence
CAUTION: Fuel system is under pressure. Before opening system, place rags around the connection point. Then release pressure by carefully loosening connection.
- Remove upper part of intake manifold Service and Repair
NOTE: Seal the intake channels in lower part of intake manifold using a clean rag.
- Disconnect fuel injector connectors.
- Disconnect vacuum hose from fuel pressure regulator.
- Remove mounting bolts from fuel distributor.
- Remove air hose for air cleaned fuel injectors at air pipe (item 4 ).
- Lift fuel rail with fuel injectors off lower part of intake manifold and support it.
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test
Checking Proper Seal
- Switch ignition on.
Vehicles with engine code AEG
- Bridge sockets 2 + 4 of test box with the respective adapter cables. Fuel Pump (FP) must run.
Vehicles with engine code AVH, AZG
- Bridge sockets 2 + 65 of test box with the respective adapter cables. Fuel Pump (FP) must run.
Continuation for all vehicles
- Check proper seal of fuel injectors (visual inspection). With Fuel Pump (FP) running, only 1 to 2 drops per minute should escape from each valve.
- Disconnect connection between test box sockets.
- Switch ignition off.
If fuel loss is greater:
- Replace malfunctioning fuel injector, item 7.
Note the following when installing the fuel injectors:
- Replace O-rings on all fuel injectors and wet them slightly with clean motor oil.
- Insert fuel injectors into fuel rail perpendicular and in the right position, and secure them with retaining clips.
- Position fuel distributor on lower part of intake manifold using secured fuel injectors and apply uniform pressure to press it in.
- The connectors must audibly engage on valves when attached.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
Checking Injection Quantity
- Insert a fuel injector to be tested into a measuring tube of VAG1602 tester for fuel injection quantity.
- Using respective adapter cables, connect one terminal of fuel injector to be checked to engine Ground (GND).
- Use adapter cable to connect second terminal of fuel injector to VAG1348/3 remote control with VAG1348/3-2 adapter cable.
- Connect alligator clip to B+.
- Switch ignition on.
Vehicles with engine code AEG
- Bridge sockets 2 + 4 of test box with the respective adapter cables. Fuel Pump (FP) must run.
Vehicles with engine code AVH, AZG
- Bridge sockets 2 + 65 of test box with the respective adapter cables. Fuel Pump (FP) must run.
Continuation for all vehicles
- Operate remote control for 30 seconds.
- Repeat test on other fuel injectors. Use new graduated measuring glasses for this.
NOTE: Also check spray pattern when checking injection quantity. Spray pattern must be the same for all injectors
- After all fuel injectors have been activated, place graduated measuring glasses on a level surface and compare quantity of injected fuel. Specified value: 85 to 105 ml. per injector
- Disconnect connection between test box sockets.
- Switch ignition off.
If the measured value of one or more fuel injectors is below or above the indicated specified value:
- Replace malfunctioning fuel injector, item 7.
Note the following when installing the fuel injectors:
Replace O-rings on all fuel injectors and wet them slightly with clean motor oil.
Insert fuel injectors into fuel rail perpendicular and in the right position, and secure them with retaining clips.
Position fuel distributor on lower part of intake manifold using secured fuel injectors and apply uniform pressure to press it in.
The connectors must audibly engage on valves when attached.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes