Checking injection quantity, leak tightness and spray pattern of injectors — AUDI

ALG
Special tools,
testers and auxiliary items required

V.A.G 1348/3-2
V.A.G 1348/3A
V.A.G 1594 A
V.A.G 1602
VAS 5051

or

V.A.G 1551 with V.A.G 1551/3 A

Test requirements:

Fuel pressure OK, checking =>Page
24-33
.

Remove intake hose between air mass meter and intake silencer.
Unplug connectors from injectors.

Unbolt fuel manifold from intake manifold.
Pull vacuum hose off fuel pressure regulator.
Lift fuel manifold, together with injectors, off intake manifold and support it.

Leak test

Connect fault reader V.A.G 1551 => Page
01-2
.
Switch the ignition on.
Start final control diagnosis => Page
01-82
and actuate injector, cylinder 1 -N30.
The fuel pump should run.

Final control diagnosis
⇒
Injector, cylinder 1 -N30
Display readout:

Note:

This step is merely designed to make the fuel pump run with the engine stopped.

Check injectors for leaks (visual check). When the fuel pump is running, only 1 or 2 drops a minute should escape from each injector.
If the fuel loss is greater, switch off the fuel pump (terminate final control diagnosis) and renew the faulty injector.

Note:

Renew O-ring.

Checking injection quantity

Place the injector which is to be tested into a measuring glass from injection quantity tester V.A.G 1602.

Connect one of the injector contacts to the engine earth using a test cable and crocodile clip from V.A.G 1594 A.
Connect second contact of injector with remote control V.A.G 1348/3A, adapter lead V.A.G 1348/3-2 and auxiliary cable to positive.
Start the final control diagnosis => Page
01-82
. The fuel pump should run.

Note:

The final control diagnosis cannot be re-started until the ignition has been switched off briefly.

Activate remote control V.A.G 1348/3A for 30 seconds.
Once all three injectors of a cylinder bank have been actuated, place the three measuring glasses on a flat surface.
Specified value per injector: 90 ... 125 ml

If the measured value for one or more of the injectors is outside the tolerance range, switch off the fuel pump (terminate final control diagnosis) and renew the defective injector.

Repeat the check on injectors of second cylinder bank.
If the measured values for all the injectors are outside the tolerance range, check the fuel pressure => Page
24-33
.

Note:

When checking the injection quantity, also check the spray pattern. The spray pattern should be the same for all the injectors.

Installation of the fuel manifold together with injectors is performed in the reverse sequence. The following points should be noted when installing:

Renew the O-rings at all opened connections. (When renewing the front O-ring, make sure not to remove the plastic cap from the injector head. The O-ring must be pulled over the plastic cap).
Moisten the O-rings with clean engine oil.
Insert injectors perpendicularly and in correct position into fuel manifold and secure with fasteners.
Place fuel manifold with secured injectors in position at intake manifold and press in evenly.