Daewoo Nubira. Manual - part 133

ENGINE CONTROLS  1F – 389

DAEWOO V–121 BL4

OXYGEN SENSOR

Removal Procedure

1.  Disconnect the negative battery cable.

Notice : The oxygen sensor (O2S 1) uses a permanently
attached pigtail and connector. This pigtail should not be
removed from the O2S 1. Damage or removal of the pigtail
or the connector could affect proper operation of the O2S
1. Take care when handling the O2S 1. Do not drop or
damage the O2S1.

2.  Disconnect the O2S 1 connector.

Notice : The oxygen sensor may be difficult to remove
when the engine temperature is below 118?F (48?C). Ex-
cessive force may damage the threads in the exhaust
manifold.

3.  Carefully remove the O2S 1 from the exhaust man-

ifold.

Installation Procedure

Important : A special anti–seize compound is used on the
O2S 1 threads. This compound consists of a liquid graph-
ite and glass beads. The graphite will burn away, but the
glass beads will remain, making the sensor easier to re-
move. New or service sensors will already have the com-
pound applied to the threads. If a sensor is removed from
any engine and if for any reason it is to be reinstalled, the
threads must have anti–seize compound applied before
reinstallation.

1.  Coat the threads of the O2S with an anti–seize

com–pound, if needed.

2.  Install the O2S into the exhaust manifold.

Tighten

Tighten the oxygen sensor to 41 NSm (30 lb–ft).

3.  Connect the O2S connector.
4.  Connect the negative battery cable.

HEATED OXYGEN SENSOR

Removal Procedure

1.  Disconnect the negative battery cable.
2.  Disconnect the electrical connector.

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ENGINE CONTROLS

DAEWOO V–121 BL4

3.  Remove the heated oxygen sensor (HO2S 2).

Installation Procedure

1.  Install the HO2S 2.

Tighten

Tighten the heated oxygen sensor to 30 lb–ft 41 N

S

m).

2.  Connect the electrical connector.
3.  Connect the negative battery cable.

ENGINE CONTROLS  1F – 391

DAEWOO V–121 BL4

INTAKE AIR TEMPERATURE
SENSOR

Removal Procedure

1.  Disconnect the negative battery cable.
2.  Disconnect the intake air temperature (IAT) sensor

connector.

3.  Remove the IAT sensor by pulling it out of the air

in–take tube.

Installation Procedure

1.  Insert the IAT sensor into the air intake tube.
2.  Connect the IAT connector.
3.  Connect the negative battery cable.

IDLE AIR CONTROL VALVE

Removal Procedure

1.  Disconnect the negative battery cable.
2.  Disconnect the Idle Air Control (IAC) valve connec-

tor.

3.  Remove the IAC valve retaining bolts.

Notice : On IAC valves that have been in service, do not
push on the valve pintle. The force required to move the
pintle may damage the threads on the worm drive.

4.  Remove the IAC valve.
5.  Clean the IAC valve O–ring seal area, the pintle

valve seat and the air passage with a suitable fuel
system cleaner. Do not use methyl ethyl ketone.

Installation Procedure

Important : If installing a new IAC valve, be sure to re-
place it with an identical part. The IAC valve pintle shape
and diameter are designed for the specific application.
Measure the distance between the tip of the IAC valve
pintle and the mounting flange. If the distance is greater
than 28 mm, use finger pressure to slowly retract the
pintle. The force required to retract the pintlewill not dam-
age the IAC valve. The purpose of the 28 mmsetting is to
prevent the IAC pintle from bottoming out on the pintle
seat. This 28 mm setting is also an adequate setting for
controlled idle on a restart.

1.  Lubricate a new O–ring with engine oil. Install the

new O–ring onto the valve.

2.  Install the IAC valve into the throttle body.

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ENGINE CONTROLS

DAEWOO V–121 BL4

3.  Install the IAC valve retaining bolts.

Tighten

Tighten the idle air control valve retaining bolts to 27
lb–in (3 N

S

m).

4.  Connect the IAC valve connector.
5.  Connect the negative battery cable.
6.  Start the engine and check for the proper idle

speed.

MANIFOLD ABSOLUTE PRESSURE
SENSOR

Removal Procedure

1.  Disconnect the negative battery cable.
2.  Disconnect the negative battery cable.
3.  Disconnect the Intake Air Temperature (IAT) sensor

connector.

4.  Disconnect the breather hose from the valve cover.

Remove the air intake tube.

5.  Disconnect the throttle cable from the throttle body

and bracket.