Daewoo Musso. Manual - part 171

1F2-44  M161 ENGINE CONTROLS

Removal & Installation Procedure

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When removing the ECU only

1. Turn the ignition switch to "OFF" position.

2. Disconnect the negative battery cable.

3. Disconnect the couplings from ECU.

4. Unscrew the left and right bolt (3) on bolt (1) and auxiliarly

bracket and remove the auxiliarly bracket from the bracket
assembly (2).

Installation Notice

5. Unscrew the four bolts (5) and disconnect the ECU (6) from

the bracket assenbly.

Installation Notice

6. Installation should follow the removal procedure in the

reverse order.

Tightening Torque

6 - 8 Nm

5 - 7 Nm

(1)

(3)

Tightening  Torque

5 - 7 Nm

8. Unscrew the bolts (5) and disconnect the ECU (6) from  the

bracket assenbly.

Installation Notice

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When Removing the ECU with ABS or ABS/ASR Unit

1. Turn the ignition switch to "OFF" position.

2. Disconnect the negative battery cable.

3. Disconnect the couplings from ECU.

4. Disconnect the coupling from ABS or ABS/ASR unit.

5. Unscrew the bolt (1) and the left and right flange nuts.

6. Remove the ECU with ABS or ABS/ASR unit assembly.

7. Unscrew the left and right bolt (3) on the auxiliary bracket

and remove the auxiliary bracket from the bracket assembly.

Installation Notice

Tightening  Torque

6 - 8 Nm

Tightening  Torque

5 - 7 Nm

Tightening  Torque

5 - 7 Nm

9. Installation should follow the removal procedure in the

reverse order.

M161 ENGINE CONTROLS  1F2-45

1 Vacuum Hose
2 Circlip
3 Fuel Pressure Regulator

FUEL PRESSURE REGULATOR

4 O-ring ..................................................... replace
5 O-ring ..................................................... replace

1F2-46  M161 ENGINE CONTROLS

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.

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.

<Operating at Idle and partial 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.

<Operating at full load>

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.