fuel pump AUDI A4 1998 B5 / 1.G AEB Engine Motronic MFI And Ignition System

24-93

Fuel pressure regulator and residual
pressure, checking

The fuel pressure regulator controls the fuel
pressure depending on intake manifold
pressure.

Required special tools and test equipment

Pressure tester VAG 1318
Adapter 1318/11
Adapter 1318/12
Adapter 1318/13

Test requirements
Fuel pump delivery rate must be OK;
checking:

Repair Manual, Fuel Supply System, Repair
Group 20.


Checking
Pa
ge 127 of 135 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1

24-96
If residual pressure still drops below 2.5 bar (36
psi), possible malfunctions are:

Leaking connection between pressure tester
and fuel line
Leaking connection between fuel supply line
and fuel rail
Faulty check valve in fuel pump; removing and
installing:

Repair Manual, Fuel Supply System, Repair
Group 20

If residual pressure no longer drops below 2.5
bar (36 psi), the possible malfunctions are:

Leaking fuel pressure tester connections after
shut-off valve.
Faulty fuel pressure regulator
Leaking fuel injectors

Note:
Pa
ge 131 of 135 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1