1998 SSANGYONG MUSSO Vacuum

1F1-30 M162 ENGINE CONTROLS
Failure
codeItemChecking method Te s t
stepRequirementSpecified
valuePossible cause
3.2 - 3.6 bar· ·· ·
· Fuel
pressure:in
idling speed
- When the
vacuum is
applied· Engine:in idling
- Close the valve
screw on pressure
testerÞ 1.0 Connect the fuel
pressure test plug to
the pressure tester
(refer to the flgure on
previous page).· Þ Fuel pump test
· Fuel pressure
regulator
3.7 - 4.2 bar
· ·· ·
· Fuel
pressure:in
idling speed
- When the
vacuum is
not applied· Engine:in idling
- Close the valve
screw on pressure
tester Þ 2.0 Connect the fuel
pressure test plug to
the pressure tester
(refer to the flgure on
previous page).· Fuel pressure
regulator
> 3.0 bar
· ·· ·
· Fuel system
internal
leakage:· Engine:stop Þ 3.0 Connect the fuel
pressure test plug to
the pressure tester
(refer to the flgure on
previous page).· The pressure drops
rapidly:non-return
valve in fuel pump
> 2.5 bar· After 30 minutes from
engine stop· The pressure drops
slowly:
- Injector test
- Fuel pressure
regulator
- O-ring

1F1-46 M162 ENGINE CONTROLS
1 Vacuum Hose
2 Circlip
3 Fuel Pressure Regulator
FUEL PRESSURE REGULATOR
4 O-ring ..................................................... replace
5 O-ring ..................................................... replace

M162 ENGINE CONTROLS 1F1-47
3. Disconnect the vacuum hose.
4. Disconnect the circlip and remove the fuel pressure
regulator.
5. Apply the oil to O-ring lightly and then replace it.
6. Installation should follow the removal procedure in the
reverse order.
7. Check for fuel pressure and internal leaks by operating the
engine. 2. Discharge the pressure in fuel supply system by pressing
the service valve.
Removal & Installation Procedure
1. Remove the fuel pressure test connector.

1F1-48 M162 ENGINE CONTROLS
A . Valves Closed
B. Valves Opened
The pressure difference between the fuel pressure and the
intake manifold is about 3.8 bars during the full load.

The spring chamber(9) is connected to the intake manifold
with the vacuum hose at the intake pipe connection(7). The
negative pressure generated in the intake manifold activates
the diaphragm, and thus the fuel pressure gets reduced to the
rate of the operating extent of the diaphragm by the intake
manifold's negative pressure.
Consequently, the fuel pressure in the fuel distributor changes
by the intake manifold's negative pressure, and the injector's
fuel pressure gets reduced independently to the throttle valve's
position. Thus, the fuel injection volume can only be determined
according to the injector's injecting duration.
2. Fuel return line
3. Valve
5. Diaphragm
6. Compression Spring
8. Fuel Chamber
9. Spring Chamber
1. Fuel Pressure Regulator
2. Intake Manifold
3. Fuel Return(to fuel tank)
4. Fuel Supply(form fuel pump)
5. Fuel Pressure(approx. 3.8 bars)
6. Intake Manifold Negative Pressure(0 bar)
Function of the Fuel Pressure Regulator
The fuel pressure regulator maintains the fuel pressure in the
fuel line with the pressure of 3.2 bars to 3.8 bars according to
the intake manifold pressure. This operating pressure cannot
be changed, and the fuel injection volume will be only
determined by the injection time. Over supplied fuel returns to
the fuel tank through the return line.

There is no negative pressure applied to the spring chamber(9)
during the full load, and it is separated from the fuel chamber(8)
by the diaphragm(5).
When the fuel pressure goes up, the diaphragm forces the
compression spring(6) in the direction of compression . At this
moment, the valve(3) sticks to the diaphragm by the fuel
pressure, and the fuel return line(2) opens. The fuel over
supplied returns to the fuel tank through the return line.

1F1-50 M162 ENGINE CONTROLS
1 Vacuum Hose
2 Fuel Return Line...................................25-30Nm
3 Fuel Supply Line...................................25-30Nm
4 Injector Connector
FUEL DISTRIBUTOR
Preceding Work : Removal of intake air duct
5 Bolt (M8 X 50)................................22.5-27.5 Nm
6 Fuel Distributor
7 O-ring ..................................Replace if damaged
8 Injector

M162 ENGINE CONTROLS 1F1-51
Removal & Installation Procedure
1. Discharge the fuel pressure from the fuel pressure test
connector.
2. Disconnect the battery ground cable.
3. Disconnect the vacuum hose from the fuel pressure
regulator.
4. Remove the cable guide.
5. Remove the fuel return and supply line.
Notice
lFor removal, cover around parts with cloths not to be
stained by fuel.
lIn case of checking the injector only, do not remove the
fuel return and supply line.
Installation Notice
6. Remove the six injector connectors.
7. Remove the two left and two right bolts and one center bolt
of the fuel distributor assembly from the intake manifold.
Installation Notice
Tightening Torque25 - 30 Nm
Tightening Torque 22.5 - 27.5 Nm

1F1-52 M162 ENGINE CONTROLS
8. Remove the injectors and the fuel distributor carefully.
9. Installation should follow the removal procedure in the
reverse order.
10. Check for fuel pressure and internal leakage by operating
the engine.
Fuel Pressure Test
1. Turn the ignition switch to "OFF" position.
2. Remove the fuel pressure test connector.
Vacuum Hose Connected (bar) 3.2 - 3.6
Vacuum Hose Disconnected (bar) 3.7 - 4.2
5. Replace the pressure regulator diaphragm if out of the
specification. 3. Connect the fuel pressure gauge to the fuel pressure test
connector.
4. Test the fuel pressure at idling by operating the engine.

M162 ENGINE CONTROLS 1F1-63
4. Remove the line to canister and measure the pressure with
the vacuum pressure gauge.
Test
1. Maintain the normal temperature and idling state by
operating the engine.
2. Connect the ECU terminal No.11 and No.34 and check for
normal operation through the output waves using the
scanner.
Notice
Test during purge control switchover valve operation after
the minimum of 1 minute after the engine turned on.
3. Connect the ECU terminal No.34 and No.10 and check for
current consumption during the ignition switch ON.
Purge switchover valve output wave Specified Value
0.3 - 0.5
Specified Value > 50mbar
(after approx. 1min.)
purge switchover valve
operates at this time
Notice
Test while at normal temperature and at idling state by
operating the engine.