engine AUDI A4 2000 B5 / 1.G AWM Engine Motronic Injection System Servicing Owner's Manual

24-33

Checking system pressure

- Open fuel filler flap briefly (pressure release).

WARNING!
Fuel system is under pressure! Before opening system, place rags
around the connection point. Then release pressure by carefully
loosening connection. - Remove engine cover (arrows).

- Open threaded connection (arrow) and catch exiting fuel using a rag.
- Connect VAG1318 pressure gauge in supply line using adapters
1318/11, 1318/12 and 1318/13.
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- Open shut-off valve of pressure gauge. The lever points in the direction
of flow.
- Start engine and let run at idle.
- Measure fuel pressure.

Specification: about 3.5 bar positive pressure

- Disconnect vacuum hose at fuel pressure regulator.

Fuel pressure must rise to about 4.0 bar positive pressure.
- Switch ignition off.
- Check for proper seal and residual pressure by observing pressure
drop on pressure gauge.
After 10 minutes, there must be at least 2.5 bar positive pressure
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If residual pressure sinks below 2.5 bar positive
pressure:

- Start engine and let run at idle.

If pressure does not drop now:
If pressure drops again:
If pressure does not drop now: - Wait until pressure has dropped, and then switch off ignition.
Simultaneously close shut-off valve of VAG1318 pressure gauge (lever
perpendicular to direction of flow -arrow-).
- Observe pressure drop on pressure gauge.
- Test check-valve on Fuel Pump (FP).
- Open shut-off valve of pressure gauge. The lever points in the direction
of flow.
- Start engine and let run at idle.
- Wait until pressure has dropped, and then switch off ignition.
Simultaneously clamp return line (with blue marking) completely
closed.
- Replace fuel pressure regulator
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Checking internal resistance

- Remove engine cover (arrows).
- Disconnect connector at the fuel injector to be tested.

If specified value is not obtained:
If specified value is obtained: - Connect multimeter at valve for resistance measurement.

Specification: 12 to 13 (at room temperature)
- Replace fuel injector.
- Check voltage supply
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Checking voltage supply

Test requirements:

Fuse for fuel injectors OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations

Fuel Pump (FP) relay OK; checking Page 24
-52
.

- Disconnect harness connector at the fuel
injector to be tested.

If LED does not light up: - Connect VAG1527B voltage tester as follows:Harness connector
Terminal
Measure to
1 Engine Ground (GND)
- Switch ignition on.

LED must light up.
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- Repair open circuit if necessary.
If LED lights up:

- Activation of fuel injectors, checking

Checking activation

Test requirement:

Internal resistance of valve OK

- Slide back rubber grommet of fuel injector
connector, but leave connector connected.

Note:
Voltage testers do not go out completely during low current pick-up
between activations by the ECM, but rather continue to glow a little and
then get slightly brighter during activation. - Connect VAG1527B voltage tester between sockets 2 (signal) and 1
(B+).
- Operate starter briefly (engine can also start).

LED must blink.
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If LED does not blink:

- Connect VAG1598/31 test box at wiring harness
to Engine Control Module (ECM), do not connect
ECM Page 24
-19
.

If wire connection is OK: - Check the following wire connections for open circuit and short circuit
to Ground (GND) and B+: Cylinder
Fuel injector harness connector
Terminal
VAG1598/31 test box
Socket
1 2 96
2 2 89
3 2 97
4 2 88
- Repair open circuit or short circuit if necessary.
- Replace Engine Control Module (ECM) Page 24
-22
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Fuel rail with fuel injectors, disassembling
and assembling

1 -
Fuel injector insert-3 Nm
use fluid securing material D 000 600 A2 to
insert.
2 -
O-ring Removing and installing Page 24
-45
Always replaceCoat with clean engine oil
3 -
Fuel injector Cylinder 1 Fuel Injector -N30-Cylinder 2 fuel injector -N31-Cylinder 3 fuel injector -N32-Cylinder 4 fuel injector -N33-Removing and installing Page 24
-45
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4 -
O-ring
Removing and installing Page 24
-45
Always replaceCoat with clean engine oil
5 -
Fuel distributor
6 -
Fuel supply line Tighten to 25 Nm
7 -
Fuel return line
8 -
Harness connector for injectors4x
9 -
Socket head bolt- 10 Nm
10 -
Fuel pressure regulator
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Repair Manual, 1.8 Liter 4
-Cyl. 5V Engine
Mechanical, Engine Code(s): AWM, Repair Group 15; Cylinder head, removing and installing; Intake manifold, removing and installing
11 -
O-ring
Always replace
12 -
O-ring Always replace
13 -
Retaining clip For fuel pressure regulator
14 -
Retaining clip Make sure clip is correctly seated on fuel
injector and fuel rail
15 -
Intake manifold With throttle valve control module -J338-with Intake Air Temperature (IAT) sensor -
G42- Removing
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