Fuel Injectors For Injection Quantity and Proper Seal, Checking

Special tools and equipment







- VAG 1348/3 remote control
- VAG 1348/3-2 adapter
- VAG 1602 tester for quantity of injected fuel
- VAG 1594A connector test kit
- VAG 1598/31 adapter cable

Test requirement
- Fuel pressure must be OK, checking. Fuel Pressure Regulator and Residual Pressure, Checking


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


Test sequence







- Connect VAG 1598/31 adapter cable to control module wiring harness. Engine Control Module (ECM) is not connected.

I - Engine code ATW
II - Engine codes AUG, AWM







- 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.
- Bridge test box sockets 1 and 65 using auxiliary wires from VAG 1594 connector test kit.


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
- 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.

If fuel loss is greater:
- Switch off ignition and replace leaking fuel injector.


NOTE: Always use new sealing rings.


Checking Injection Quantity
- Place a fuel injector to be tested into a graduated measuring glass of tester for quantity of injected fuel VAG 1602.







- Use adapter cables from the VAG 1594 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 VAG 1348/3 remote control with VAG 134813-2 adapter wire.
- Connect alligator clip to B+.
- Bridge test box sockets 1 and 65 using auxiliary wires from VAG 1594 connector test kit.


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


- Switch ignition on.
- Operate VAG 1348/3 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: 133 to 157 ml. per injector


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


- Replace faulty fuel injector

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