Fuel Injector Leakage, Injection Quantity and Spray Pattern, Checking

Fuel Injector Leakage, Injection Quantity And Spray Pattern, Checking







Special tools and equipment
- VAG 1348/3A
- VAG 1594 A
- VAG 1598/31
- VAG 1602

Test requirement:
- Fuel pressure OK. Testing.

Test sequence
- Remove fuel rail (together with injectors) from intake manifold. Do not disconnect the fuel hoses.
- Connect test box VAG 1598/31 to wiring harness for engine control module. Do not connect to the engine control module itself.

Testing for leaks
- Bridge contacts 1 and 65 on the test box using test leads from adapter set VAG 1594 A.
- Switch on ignition.
- The fuel pump should run.
- Check injectors for leaks (visual check). When the fuel pump is running, only 1 or 2 drops should escape per minute from each injector.
- If a greater amount of fuel escapes, switch off the fuel pump (switch off ignition) and replace the faulty injector.

Checking injection quantity
- Place the injector which is to be tested into a measuring glass from injection quantity tester VAG 1602.







- Connect one of the injector contacts to engine Ground using test lead and crocodile clamp from VAG 1594 A.
- Connect second injector contact to positive using remote control VAG 1348/3 A, adapter cable VAG 1348/3-2 and auxiliary cable.
- Bridge contacts 1 and 65 on the test box using test leads from adapter set VAG 1594 A.
- Switch on ignition.
- The fuel pump should run.
- Activate remote control VAG 1348/3A for 30 seconds.
- Carry out measurement on all injectors.
- Once all four injectors have been actuated, place measuring glasses on a level surface.
- Specification for each injector: 145 ± 12 ml
- If the measured value for one or more of the injectors is outside the tolerance range, switch off the fuel pump (by switching off ignition) and replace the defective injector.
- If the measured values for all the injectors are outside the tolerance range, check the fuel pressure. Fuel Pressure Regulator and Residual Pressure, Checking

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

- Install injectors together with fuel rail.