Fuel Injectors, Checking

Fuel Injectors, Checking

Checking fuel injectors for injection quantity and leaks

Special tools, testers and auxiliary items required
- Remote control V.A.G 1348/3A with adapter cable V.A.G 1348/3-3
- Injector quantity testing device V.A.G 1602
- Adapter cable V.A.G 1348/3-2

Fuel injectors, checking for leaks and quantity injected
- Fuel pressure must be OK, checking. Fuel Pressure


Checking for leaks

CAUTION: Fuel supply lines are under pressure. Wear protective goggles and protective gloves to avoid damage and contact with skin. Before removing from hose connection wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.

- Remove fuel rail completely (fuel lines remain connected) Fuel rail, assembly overview,
- Remove cover over fuse holder.







- Pull fuel pump relays - 1 - and - 2 - out of their sockets.







- Connect remote control V.A.G 1348/3 with adapter cable V.A.G 1348/3-3 to connection - arrow - for fuel pump relay for right fuel delivery unit.







- Connect second connection of adapter cable V.A.G 1348/3-3 - arrow - to connection to fuel pump relay for left fuel delivery unit.







- Connect alligator clip of remote control V.A.G 1348/3 to positive connection - 1 -.
- Operate remote control V.A.G 1348/3

If fuel pump is activated:
- Check injectors for leaks (visual inspection). Only 1 to 2 drops per minute may emit from each valve when fuel pump is running.

If fuel loss is greater:
- Replace faulty fuel injector.
When installing fuel injector, observe the following:
- Replace O-rings on all injectors and lightly moisten with clean engine oil.
- Insert fuel injectors into fuel rail perpendicular and in correct position, and secure them with retaining clips.
- Position fuel rail with secured fuel injectors on intake manifold and apply uniform pressure to press it in.

Injection quantity, checking
- Fuel pump relays and fuses 13 and 14 are in their sockets.
- Connect test box V.A.G 1598/31 to Engine Control Module (ECM).







- Bridge test box sockets 1 and 65 using adapter cables from connector test set V.A.G 1594.
- Insert injector to be tested in a measuring glass of calibration tester V.A.G 1602.







- Using jumper wires from connector test set V.A.G 1594 connect one terminal of fuel injector to be checked to engine Ground (GND).
- Connect second fuel injector terminal with adapter cable to remote control V.A.G 1348/3 using adapter cable V.A.G 1348/3-2.







- Connect alligator clip of remote control V.A.G 1348/3 to battery (+) - 1 - in engine compartment.
- Switch ignition on. Operate remote control V.A.G 1348/3 for 30 seconds.
- Repeat check on other injectors. To do this use new measuring beakers.
- Switch off ignition.
- After all injectors have been activated, place measuring glasses on a horizontal surface and compare injected quantity. Specified value: 95 to 115 ml per injector

If measured value of one or more fuel injectors is below or above the indicated specified value:
- Replace faulty fuel injector

Perform installation of injectors in reverse order. When doing this note the following:
- Replace O-rings on all injectors and lightly moisten with clean engine oil.
- Insert fuel injectors into fuel rail perpendicular and in correct position, and secure them with retaining clips.
- Position fuel rail with secured fuel injectors on intake manifold and apply uniform pressure to press it in.