Fuel Injectors For Injection Quantity and Proper Seal, Checking

Checking Fuel Injectors For Injection Quantity and Proper Seal







Special tools and equipment
- VAG1348/3 remote control
- VAG1348/3-2 adapter
- VAG1602 tester for quantity of injected fuel

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

Test sequence
- Remove the fuel rail completely (fuel lines remain connected). Intake manifold, lower part, disassembling and assembling
- Remove intake manifold for this:

Checking Proper Seal
- Initiate output Diagnostic Test Mode (DTM); Fuel Pump (FP) must be running. [1][2][3]Output Diagnostic Test Mode (DTM) (Function 03)

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


- 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.


NOTE: Output Diagnostic Test Mode (DTM), and therefore the Fuel Pump (FP), is switched off after one minute.

If fuel loss is greater:
- Switch ignition off.
- Replace faulty fuel injector.

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 distributer on lower part of intake manifold using secured fuel injectors and apply uniform pressure to press it in.

Checking Injection Quantity







- Connect VAG1598/31 test box to control module wiring harness. Engine Control Module (ECM) is not connected.
- Switch ignition on.
- Bridge sockets 2 + 65 of test box using adapter cables from VAG1594 connector test kit. Fuel Pump (FP) must be running.
- Place a fuel injector to be tested into a graduated measuring glass of tester for quantity of injected fuel VAG1602.







- Use adapter cables from the VAG1594 connector test kit to connect one terminal of tested fuel injector to engine Ground (GND).
- Use adapter cable to connect second terminal of fuel injector to VAG1348/3 remote control with VAG1348/3-2 adapter wire.
- Connect alligator clip to B+.
- Operate VAG1348/3 remote control for 30 seconds.
- Repeat test on other fuel injectors. Use new graduated measuring glasses for this.
- After all fuel injectors have been activated, place graduated measuring glasses on a level surface and compare quantity of injected fuel. Specification: 110 to 130 ml per injector


NOTE: If the measured value of one or more fuel injectors is below or above the indicated specified value:


- Switch ignition off.
- Replace faulty fuel injector.

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 distributer on lower part of intake manifold using secured fuel injectors and apply uniform pressure to press it in.
- Check DTC memory, repair any malfunctions and then erase DTC memory.

After successful repair:
- Read readiness code. If DTC memory was erased or the Engine Control Module (ECM) was disconnected from the continuous B+ supply, the readiness code must be re-generated. Monitors, Trips, Drive Cycles and Readiness Codes Monitors, Trips, Drive Cycles and Readiness Codes