Fuel Injector: Testing and Inspection

Checking Activation
Check Activation Of Fuel Injectors: See Output Diagnostic Test Mode
Function 03.

Special Tools, Testers And Auxiliary Items
- VAG 1598/18 Test Box
- Multimeter (Fluke 83 Or Equivalent)
- VAG 1527B Voltage Tester
- Connector Test Kit VW 1594
- Wiring Diagram

Check Conditions
- Engine speed sensor OK.
- Fuel pump relay OK.

Test Sequence
- Remove intake manifold, upper.




- Disconnect harness connector -1- from connection -2- and connect VAG 1527B voltage tester with test leads from VW 1594 to the terminals of the harness connector.
- Disconnect harness connectors from fuel injectors 2-4.
- Operate starter and check the voltage supply for no. 1 cyl. fuel injector.
- LED must flicker.
- Repeat check on fuel injectors 2-4.

If the LED does not flicker:
- Switch ignition off.




- Connect VAG 1598/18 test box to ECM wiring harness.




- Check wiring between test box and connector for open circuit according to wiring diagram.
- No. 1 cyl. fuel injector: terminal 2 and test box socket 24
- No. 2 cyl. fuel injector: terminal 2 and test box socket 25
- No. 3 cyl. fuel injector: terminal 2 and test box socket 26
- No. 4 cyl. fuel injector: terminal 2 and test box socket 02
Resistance: Maximum 1.5 ohms
- Check wiring between fuel injector connector terminal 1 and relay panel for open circuit according to wiring diagram.
Resistance: Maximum 1.5 ohms
- Additionally, check wires for short circuit to one another.
Specification: Infinite Ohms

Checking Resistance Of Fuel Injectors




- Check resistance of fuel injectors individually
Specification: 15-20 ohms

If the specification is not attained, replace fuel injectors as necessary.

Checking Spray Pattern And Checking For Leaks


WARNING:
- DO NOT Smoke Or Work Near Heaters Or Other Fire Hazards When Working On Fuel System.
- The Fuel System Is Pressurized! Before Loosening Hose Connections Or Opening The Test Connection, Wrap A Cloth Around The Connection. Then Release Pressure By Slowly Disconnecting The Hose/fitting.


Special Tools, Testers And Auxiliary Items
- Connector test kit VW 1594
- VAG 1630 digital potentiometer
- VAG 1602 fuel analyzer

Test Sequence
- Remove intake manifold, upper.
- Remove fuel rail complete with fuel injectors.




- Hold Fuel Injectors In VAG 1602 Fuel Analyzer.




- Disconnect harness connector from Engine Coolant Temperature sensor -G62-.
- Set digital potentiometer VAG 1630 side A to 15 K Ohms and using test leads from VW 1594 connect to terminals 1 and 3 of disconnected harness connector.
- Disconnect harness connector from ignition coil.
- Operate starter (Second Technician Required).
- The fuel injectors must pulsate and spray in accordance with firing order.
- Switch ignition off and check fuel injectors for leaks.
- No more than 2 drops/minute may leak from each fuel injector.


NOTE: When installing the fuel injectors make sure that the O-rings are not damaged.