Fuel Injectors For Leaks and Quanity Injected, Checking
Injection Quantity And Proper Seal Of Fuel Injectors, Checking
Recommended special tools and equipment
- VAG 1348/3A remote control with VAG 1348/3-2 adapter cable
- V.A.G 1602 tester for quantity of injected fuel
Without illustration:
- VAG 1594A connector test kit
Test requirement
- Fuel pressure must be OK. Testing and Inspection
Test sequence
WARNING: 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.
- Intake manifold, upper part, disassembling and assembling:
- Vehicles with engine code AEG, AVH, AZG.
- Vehicles with engine code BDC.
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.
- Disconnect air hose for air cleaned fuel injectors at air pipe:
- Vehicles with engine code AEG, AVH, AZG, Item 5.
- Vehicles with engine code BDC, item 7.
- Lift fuel distributor 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, BDC
- 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 faulty fuel injector:
- Vehicles with engine code AEG, AVH, AZG, item 7,
- Vehicles with engine code BDC, item 9.
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 distributor perpendicular and in the right position, and secure them with retaining clips.
- Position fuel distributor with secured fuel injectors on lower part of intake manifold 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 VAG 1348/3 remote control with VAG 1348/3-2 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, BDC
- 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 faulty fuel injector:
- Vehicles with engine code AEG, AVH, AZG, item 7.
- Vehicles with engine code BDC, item 9.
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 distributor perpendicular and in the right position, and secure them with retaining clips.
- Position fuel distributor with secured fuel injectors on lower part of intake manifold 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