Fuel Injection Components, Checking

Fuel injection components, checking

Injectors, checking for leaks and quantity injected

Special tools and equipment





^ V.A.G. 1348/3 Remote control
^ V.A.G. 1348/3-2 Adapter
^ V.A.G. 1602 Calibration tester
^ V.A.G. 1594 A Adapter set
^ Test box V.A.G. 1598/31

Test conditions
^ Fuel pressure must be OK,.

WARNING! Fuel system is under pressure! Before opening the system remove fuse 28 and place a cloth around the connection. Then release pressure by carefully loosening the connection.

Test sequence





^ Connect test box V.A.G. 1598/31 to control module wiring harness. Engine control module remains disconnected.
^ Remove intake manifold upper part.
^ Disconnect connectors from all injectors.
^ Remove securing bolts on fuel rail.
^ Disconnect vacuum hose from fuel pressure regulator.
^ Disconnect hose from air pipe for air shrouded injectors.
^ Lift fuel rail along with injectors off intake manifold and support.
^ Bridge test box sockets 1 and 65 using adapter cable from adapter set V.A.G. 1594.

Note: This work sequence allows the fuel pump to run when the engine is not running.

^ Switch ignition on.

Checking for leaks
^ Check injector for leaks (visual check).
Only 1 to 2 drops per minute must emit from each injector when fuel pump is running.
If the fuel loss is greater:
^ Switch ignition off and replace leaky injector.
^ Erase Diagnostic Trouble Code (DTC) memory to return learned values to a neutral (default) position.

Note: Always replace seals.

Checking quantity injected

Test conditions
^ Test box V.A.G. 1598/31 still connected and test box sockets 1 and 65 are still bridged using adapter cables from adapter set V.A.G. 1594.
^ Insert injector to be checked in a measuring glass of calibration tester V.A.G. 1602.
^ Connect one contact of injector to be tested to engine Ground using adapter cables from V.A.G. 1594.
^ Using adapter cables connect the second injector contact to remote control V.A.G 1348/3 with adapter cable V.A.G. 1348/3-2.





^ Connect alligator clip to battery positive (+).
^ Switch ignition on. Fuel pump must run.
^ Operate remote control V.A.G. 1348/3 for 30 seconds.
^ Repeat check on other injectors. Use another (clean and dry) measuring beaker for this.
^ After all injectors have been activated, place measuring glasses on a horizontal surface and compare the quantity injected.
Specification: 85...105 ml. per injector
If the measured values of one or more injectors are above or below the prescribed specifications:
^ Replace faulty injector.
^ Erase DTC memory to return learned values to a neutral (default) position.
Perform installation of injectors in reverse order. When doing this note the following:
^ Replace O-rings on all injectors and moisten them lightly with clean engine oil.
^ Insert injectors vertically and in correct position into fuel rail and secure with retaining clips.
^ Set fuel rail with secured injectors on intake manifold and press in evenly.