With Generic Scan Tool

Injection Quantity And Proper Seal Of Fuel Injectors, Checking







Recommended special tools and equipment
- VAG1348/3A remote control with VAG1348/3-2 adapter cable
- VAG1602 tester for quantity of injected fuel

Without illustration:
- VAG1594A connector test kit

Test requirement
- Fuel pressure must be OK, checking. Testing and Inspection

WARNING: Fuel system is under pressure. Before opening system, place rags around the connection point. Then release pressure by carefully loosening connection.

Test sequence
- Disconnect fuel injector connectors.
- Remove mounting bolts from fuel distributor.
- Then remove the fuel distributor completely.
- Disconnect vacuum hose from fuel pressure regulator.
- Lift fuel rail with fuel injectors off 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

NOTE: The only purpose of this step is to allow the Fuel Pump (FP) to run with the engine at standstill.

- Switch ignition on.

Checking Proper Seal
- Bridge sockets 2 + 65 of test box with the respective adapter cables.
Fuel Pump (FP) must run.
- 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 10

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 with secured fuel injectors on intake manifold and apply uniform pressure to press it in.

- 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.
- Bridge sockets 2 + 65 of test box with the respective adapter cables.
Fuel Pump (FP) must run.
- Operate remote control (VAG1348/3) 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: 133 to 165 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 10

Installation of fuel injectors is the same in reverse order. Note the following:
- 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 with secured fuel injectors on intake manifold and apply uniform pressure to press it in.

- 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