Vacuum SSANGYONG MUSSO 1998 Workshop Owner's Guide

M161 ENGINE CONTROLS 1F2-47
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.

M161 ENGINE CONTROLS 1F2-49
FUEL DISTRIBUTOR
Preceding Work : Removal of intake air duct
1 Fuel Distributor
2 Circlip
3 Fuel Pressure Regulator
4 O-ring
5 Fuel Pressure Test Connector
6 Seal Ring
7 Vacuum Hose
8 Combination Bolt (M8 X 120).........22.5-27.5 Nm9 Fuel Return Line
10 Seal Ring
11 Hollow Bolt.....................................22.5-27.5 Nm
1 2 Clamp
13 Bolt (M8 X 22)........................................ 9-11 Nm
14 Injector Bracket
15 Injector
16 O-ring

1F2-50 M161 ENGINE CONTROLS
Tightening Torque
22.5 - 27.5 Nm
Tightening Torque22.5 - 27.5 Nm
Removal & Installation Procedure
1. Discharge the fuel pressure from the fuel pressure test
connector by pushing service valve (arrow).
2. Disconnect the battery ground cable.
3. Disconnect the vacuum hose from the fuel pressure
regulator.
4. Disconnect the cable from ignition coil.
5. Remove the fuel return and supply line.
Installation Notice
Notice
lFor removal, cover around parts with cloths not to
bestained by fuel.
lIn case of checking the injector only, do not remove the
fuel return and supply line.
6. Remove the four injector connectors (arrows).
7. Unscrew the two combination bolts (8).
Installation Notice

1F2-52 M161 ENGINE CONTROLS
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.

M161 ENGINE CONTROLS 1F2-63
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.

1F2-64 M161 ENGINE CONTROLS
1 Purge Switchover Valve
2 Molded Hose
3 Fuel Tube (270 mm)
4 Clamp
5 Molded Hose
6 Intake Manifold
7 Throttle Body
VACUUM SYSTEM
Manual Transmission
8 Fuel Pressure Regulator
9 Vacuum Line Rubber Hose (40 mm)
10 Vacuum Tube (Gray, 540 mm)
11 Rubber Cap
12 Molded Hose
13 Vacuum Tube (Brown)
14 Connector

SECTION 1F3
OM600 ENGINE CONTROLS
Specifications . . . . . . . . . . . . . . . . . . . . . . . 1F3-1
Fastener Tightening Specifications . . . . . . . . 1F3-1
Maintenance and Repair . . . . . . . . . . . . . . 1F3-2
On-Vehicle Service . . . . . . . . . . . . . . . . . . . . 1F3-2
Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . 1F3-2
Fuel Injection Pump Coding . . . . . . . . . . . . . 1F3-3
Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . 1F3-4
Vacuum Control System Test . . . . . . . . . . . . 1F3-5
Vacuum Pump(Sectional View) . . . . . . . . . . 1F3-10
Vacuum Pump Test . . . . . . . . . . . . . . . . . . . 1F3-11
Vacuum Pump . . . . . . . . . . . . . . . . . . . . . . 1F3-13
Vacuum Unit Replacement . . . . . . . . . . . . . 1F3-15Idle Speed Adjustment . . . . . . . . . . . . . . . . 1F3-16
Fuel Pump Test . . . . . . . . . . . . . . . . . . . . . . 1F3-18
Fuel Pump . . . . . . . . . . . . . . . . . . . . . . . . . 1F3-21
Injection Nozzle Test . . . . . . . . . . . . . . . . . . 1F3-22
Injection Nozzles . . . . . . . . . . . . . . . . . . . . . 1F3-25
Injection Nozzle Repair . . . . . . . . . . . . . . . . 1F3-27
Removal and Installation of
Injection Timing Device . . . . . . . . . . . . . . 1F3-30
Injection Timing Device . . . . . . . . . . . . . . . . 1F3-35
Start of Delivery Test
(Position Sensor, RIV Method) . . . . . . . . . 1F3-37
Fuel Injection Pump . . . . . . . . . . . . . . . . . . 1F3-46
TABLE OF CONTENTS
Caution: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless otherwise
noted.
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
Application
Fuel Tank Mounting Nut
Fuel Pump Pressure Line
Fuel Injection Nozzle
Fuel Injection Pipe
Nozzle Tensioning Nut
Screw Plug
Left-Hand Thread BoltN·m
28 - 47
13
35 - 40
18
80
30
46

OM600 ENGINE CONTROLS 1F3-3
FUEL INJECTION PUMP CODING
Model Code
PES 4M 55C 320 RS 167
PES 5M 55C 320 RS 168
Fuel Injection Pump Code
Example)PES 5M 55C 320 RS 168
P Pump
E Self-Driven
S End Flange Mounting
5 Number of Cylinders (5EA)
M Pump Size
55 Element Diameter
C Modification Letter
320 Assembly Number
R Direction of Rotation (clockwise)
S188 Special Version
RSF Governor
R Governor
S Coil Spring
F Drive Governor
Component Location
1. Fuel Injection Pump
2. Vacuum Unit (Stop Unit)
3. Control Lever
4. PLA Vacuum Unit (Idle Speed Adjustment)
5. Governor
6. Fuel Pump
OM661 LA Engine
OM662 LA Engine

OM600 ENGINE CONTROLS 1F3-5
VACUUM CONTROL SYSTEM TEST
2 Engine Cut-Off Valve (Ignition Key Switch)
3 Auto-locking Hub Solenoid Valve
4 Engine Stop Valve Unit
5 PLA Vacuum Unit (Idle Speed Adjustment)
6 Engine
7 Vacuum Pump8 30° Thermovalve
9 Fuel Injection Pump
10 Filter with Restriction
11 Check Valve
12 Modulating Pressure Line (Automatic T/M)
Test Data
Idle Speed Increase
Permissible Pressure Drop of SystemAt least 100 rpm at approx. 500mbr
400 - 500mbar approx. 1 min.

1F3-6 OM600 ENGINE CONTROLS
Temperature measuring instrument with test probe
WB24 Digital tester Tools Required
001 589 73 21 00 Vacuum Pump
201 589 13 21 00 Vacuum Tester
667 589 00 21 00 TDC pulse generator
Commercial Tools
e.g. Bosch MOT 001.03
Sun DIT 9000
e.g. Ahlborn, Therm 2263-2
Eichenfeldstrabe 1 - 3
D-8150 Holzkirchen
Tester Connection
11 TDC Pulse Sender Unit
12 Digital Tester