engine SSANGYONG MUSSO 1998 Workshop Repair Manual

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.

M162 ENGINE CONTROLS 1F1-49
The pressure difference between the fuel pressure and
the intake manifold is approx. 3.2 bars during idling.

1. Fuel Pressure Regulator
2. Intake Manifold
3. Fuel Return(to fuel tank)
4. Fuel Supply(from fuel pump)
7. Fuel Pressure(approx. 3.2 bars)
8. Intake Manifold Negative Pressure(0.6 bars)
A. Fuel pressure
B. Intake Manifold Negative Pressure
LL. Idling
TL. Partial load
VL. Full load

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 1F1-53
3. If there is no change in fuel pressure and maintain the
following pressure over 30 minutes, it is normal.
Internal Leakage Test
1. Connect the fuel pressure gauge to the fuel pressure test
connector.
2. Stop the engine for approx. 30 minutes and then check the
fuel pressure changes.
Fuel pressure
drops slowly
·Fuel leakage at the
injector
• Faulty fuel pressure
regulator's
diaphragm and O-
ring.
Fuel pressure
drops rapidly• Faulty check valve
in the fuel pump.
Possible Cause Pressure Change
Fuel Pressure(bar) 2.5
Discharging the pressure in fuel system
1. Remove the fuel pressure test connector.
Installation Notice
2. Remove the fuel pressure in fuel system by pressing the
service valve with a clean, pointy tool.
Notice
Place a cloth so that the fuel doesn't stain around.
Tightening Torque 22.5 - 27.5 Nm

1F1-54 M162 ENGINE CONTROLS
INJECTOR
Preceding Work : Removal of fuel distributor
1 O-ring ....................................rplace, if damaged
2 Injector Bracket
3 Injector4 O-ring ..................................replace, if damaged
5 Fuel Distributor

M162 ENGINE CONTROLS 1F1-55
Removal & Installation Procedure
1. Remove the O-ring.
Check for damage and replace it if necessary.
2. Remove the injector bracket from the injector.
Installation Notice
Exactly seat the anti-twist lock into the square groove in
injector.
3. Separate the injector from the fuel distributor.
Inspection & Maintenance
Inspection of the Injector operation and spray pattern
1. Connect the contact box to the ECU.
2. Connect the shop made test plug to the injector and place
it into the tank.
3. Position the ignition switch to ON.
4. Connect the pin 63(+) and 69(-) of the contact box with a
test cable.
5. Check the injector spray pattern.
Notice
Replace the injector if the injector spray pattern is abnormal
or the fuel doesn't inject.
Injector Resistance Inspection
1. Remove the injector connector.
2. Measure the injector coil resistance using a resistance
tester.
Notice
Replace the injector if the measured values is out of the
specified values. Check the connector and wire connection
between the ECU and the injector if the measured values
are normal.
Specified Value
14 - 17 W

1F1-56 M162 ENGINE CONTROLS
The Injector Spray Pattern Check
1. Connect the test box (129 589 00 21 00) to the ECU.
2. Disconnect the connector from connector.
3. Disconnect the fuel distributor and injector with a unit from
engine without removing the fuel supply and return line.
Notice
Prepare the beaker for taking the poping fuel.
4. Connect either end of shop made cable to the injector.
5. Connect the other end of shop made cable to the No.21
(+:63)and No.3(-:69) terminal of the test box.
6. Turn the ignition switch to "ON" position.
7. Check the injector for normal spray pattern as shown in the
figure. Check injector for leaks or later drops.
Notice
Refer to fuel injector test of engine diagnosis in this section
for detailed information.