engine AUDI A4 1995 B5 / 1.G AFC Engine Multiport Fuel Injection System Servising Workshop Manual

24-12
Multiport fuel injection system, technical data

Engine code
AFC
Idle speed

Not adjustable, maintained by idle speed
control 650 - 750 RPM
RPM upper limit
Actuated by switching off fuel injectors 6200 RPM
CO content in front of Three Way Catalytic
Converter (TWC)
Not adjustable, controlled by ECM 0.2 - 1.2 Vol. %
Fuel pressure
At idle, with vacuum hose: Connected Approx. 3.2 - 3.8 bar
(46 - 55 psi)
Disconnected Approx. 3.8 - 4.2 bar
(55 - 61 psi)
Residual pressure
After 10 minutes with: Cold engine 2.2 bar (32 psi)
Warm engine 3.0 bar (44 psi)
Fuel injectors: Spray pattern: Approx. the same for all fuel
Pa
ge 6 of 13 Multi
port Fuel In
jection
(MFI
) system, servicin
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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24-13

Safety measures


WARNING!

Be alert when working on or near the engine.
High ignition secondary voltage can cause
serious personal injury and damage vehicle
components.

DO NOT touch or disconnect ignition system
wires when the engine is running or being
cranked at starting RPM.
DO NOT operate the starter if the fuel
injectors have been removed.

Be sure the ignition is switched OFF, when:
Disconnecting ignition wires
Disconnecting fuel injection system wiring
Connecting or disconnecting test equipment
leads
Disconnecting the battery
Washing the engine or engine
compartment.
Pa
ge 8 of 13 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
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pair&id=AUDI.B5.FU01.24.2

BEFORE cranking the engine at starting RPM
(such as for compression testing) disable the
ignition and fuel injection systems:

Disconnect the ignition coil power output
stage.
Disconnect harness connectors from all fuel
injectors.
After the work is completed, erase
Diagnostic Trouble Code (DTC) memory.
Pa
ge 9 of 13 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.FU01.24.2

24-14

CAUTION!

BEFORE disconnecting the battery:

Stop the engine.
Be sure the ignition is switched OFF (also
applies when connecting the battery). Failure
to do so may damage the Engine Control
Module (ECM).
Be sure of the proper radio code (for vehicles
equipped with coded anti-theft radio).

Be sure the battery negative (-) cable is
disconnected, when:
Working on the electrical system
Resistance (spot) welding or electric arc
welding anywhere on the vehicle.

When connecting and disconnecting
electrical test equipment (LED voltage tester,
multimeter, etc.):
Be sure the ignition is switched OFF.
Use correct adapters from the VW 1594
Pa
ge 10 of 13 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.FU01.24.2

connector test kit.

For any work affecting the Engine Control
Module (ECM):
BEFORE disconnecting the ECM harness
connector, switch the ignition OFF and WAIT
at least 20 seconds. Failure to do so may
damage the ECM.
DO NOT connect any outside voltage source
to stimulate an output signal at the ECM.
Pa
ge 11 of 13 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.FU01.24.2