engine oil AUDI A4 1999 B5 / 1.G APB Engine Motronic Multiport Fuel Injection System Servising Workshop Manual

24-2

CAUTION!

To operate the engine at starter speed
without actually starting it (for example, in
order to test compression), unplug the
connectors from the output stages for the
ignition coils and also the connectors on the
injectors.
During some of the tests the control module
may identify and record malfunctions. The
DTC memory should therefore be checked
and (if necessary) erased after completing
the tests and any repair work that may be
required. After erasing DTC memory
generate new readiness code Page 01
-
105
.

Always switch off the ignition before
cleaning the engine.
Always switch off the ignition before
connecting or disconnecting the battery,
otherwise the engine control module may be
damaged.
Be sure of proper radio code (for vehicles
equipped with coded anti-theft radio)

Be sure the battery negative (-) cable is
Pa
ge 3 of 90 Motronic Multi
port Fuel In
jection
(MFI
) system, servicin
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11/22/2002 htt
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24-48

Checking for leaks

- Bridge sockets 1 and 65 on the test box using
test leads from VAG1594 A connector test kit.
(This creates an Ground (GND) connection to
one side of the fuel pump relay coil.)

Note:
Once the socket are bridged the fuel pump runs
continuously, even if the engine is not running.
This is because the fuel pump relay receives its
positive voltage supply via the central electrics.
The negative voltage supply for the fuel pump
relay comes via the cable bridge on the test box.

WARNING!

Fire hazard. DO NOT smoke or work near
heaters or have anything in the area that can
ignite fuel!

- Check injectors fuel for leaks (visual check).
When fuel pump is running, only 1 or 2 drops
should escape per minute from each injector.

- If fuel loss is greater, switch off fuel pump
(remove bridge) and replace faulty injector
Page 24
-53
, also observe notes on Page 24
-
53
.
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jection
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24-49


WARNING!
Make sure test box is inside of passenger compartment.
The fuel pump should run. - Connect one fuel injector terminal to engine Ground (GND) using test
cable and crocodile clamp from VAG1594 connector test kit.
- Connect second fuel injector terminal to B+ using remote control
VAG1348/3 A, adapter cable VAG1348/3-2 and auxiliary cable.
- Bridge sockets 1 and 65 on the test box using test leads from
VAG1594 A connector test kit. (This creates an Ground (GND)
connection to one side of the fuel pump relay coil.)
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ge 59 of 90 Motronic Multi
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jection
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24-51

- Repeat test for fuel injectors from second bank
of cylinders.

- If measured values for all fuel injectors are
outside tolerance range (specification), check
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 rail together with injectors
is performed in the reverse sequence. The
following points should be noted when installing:

Replace O-rings at all opened connections.
(When replacing the front O-ring, make sure
not to remove the plastic cap from the
injector head. The O-ring must be pulled off
over the plastic cap.)
Moisten O-rings with clean engine oil.
Pa
ge 61 of 90 Motronic Multi
port Fuel In
jection
(MFI
) system, servicin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.1