fuel SSANGYONG MUSSO 2003 Workshop Manual

M162 ENGINE CONTROLS 1F1-47
3. Disconnect the vacuum hose.
4. Disconnect the circlip and remove the fuel pressureregulator.
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 CONTROLSA . 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). Thenegative 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 intakemanifold's negative pressure.
Consequently, the fuel pressure in the fuel distributor changes by the intake manifold's negative pressure, and the injector'sfuel pressure gets reduced independently to the throttle valve'sposition. 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 tothe intake manifold pressure. This operating pressure cannotbe 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 thismoment, the valve(3) sticks to the diaphragm by the fuelpressure, 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
V L . Full load

1F1-50 M162 ENGINE CONTROLS1 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 testconnector.
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
For removal, cover around parts with cloths not to be
stained by fuel.
In 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 Torque 25 - 30 Nm
Tightening Torque 22.5 - 27.5 Nm

1F1-52 M162 ENGINE CONTROLS8. 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 thefollowing 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 pressureregulator'sdiaphragm 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 Injector 4 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.
NoticeReplace 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 connectionbetween the ECU and the injector if the measured valuesare normal.
Specified Value 14 - 17

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 fromengine 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.