sensor NISSAN PULSAR 1987 User Guide
[x] Cancel search | Manufacturer: NISSAN, Model Year: 1987, Model line: PULSAR, Model: NISSAN PULSAR 1987Pages: 238, PDF Size: 28.91 MB
Page 76 of 238
Cooling and Heating Systems
7. THERMOSTAT HOUSING
Special Equipment Required:
To Adjust Camshaft Drive Belt — Adjusting tool
TO REMOVE AND INSTAL
(1) Disconnect the negative battery terminal.
(2) On 1.6 liter models, remove the air cleaner
assembly from the engine. Refer to the Fuel and
Engine Management section if necessary. (3) Drain the cooling system as previously de-
scribed. (4) Remove the camshaft drive belt as described
in the Engine section under the heading Camshaft
Drive Belt. (5) Remove the bolts retaining the camshaft
drive belt rear cover to the cylinder block and remove
the rear cover.
\ COOLANT TEMPERATURE SENSOR TEMPERATURE SENDER SWITCH
View of the thermostat housing and
components.
(6) Disconnect the top radi ator hose, the heater
hose and the inlet manifold heater hose from the
thermostat housing.
(7) Disconnect the wire from the temperature
sender switch and the coolant temperature sensor. (8) Remove the bolts retaining the thermostat
housing to the cylinder head and remove the thermo-
stat housing and the O ring from the cylinder head. Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure that all mounting faces are clean.
(2) Renew the O ring on installation.
NOTE; Ensure that the O ring is not
twisted. Do not use sealant.
(3) Tighten the thermostat housing retaining
bolts to the specified torque. (4) Adjust the camshaft drive belt tension as
described in the Engine section under the heading
Camshaft Drive Belt. (5) Fill the cooling system as previously de-
scribed and check for coolant leaks. 8. WATER PUMP
Special Equipment Required:
To Adjust Camshaft Drive Belt — Adjusting tool
TO REMOVE AND INSTAL
NOTE: The water pump is non-repairable
and if faulty must be renewed as a complete
assembly.
(1)
Drain the cooling system as previously de-
scribed.
(2) Remove the camshaft drive belt as described
in the Engine section under the heading Camshaft
Drive Belt. (3) Remove the water pump retaining bolts and
remove the water pump and the O ring from the
engine. Installation is a reversal of the removal procedure
with attention to the following points:
View of the water pump and components removed
from the vehicle.
(1) Ensure that all mounting faces are clean.
(2) Use a new O ring and smear it with a liberal
amount of silicone grease.
(3) Install the water pump to the engine but
do
not tighten the retaining bolts until the camshaft drive
belt has been installed and tensioned correctly as
described in the Engine section under the heading
Camshaft Drive Belt.
(4) Fill the cooling system as previously de-
scribed in this section and check for coolant leaks.
9. WELCH PLUGS
To facilitate the casting of the cylinder block and
cylinder head passages and water jackets, a number of
openings had to be ma de at manufacture.
Page 80 of 238
Cooling and Heating Systems
11. BLOWER FAN
TO REMOVE AND INSTAL
(1) Disconnect the negative battery terminal.
(2) Working below the glov e compartment, dis-
connect the wiring connector to the blower fan motor.
(3) Remove the bolts retaining the blower fan
motor and carefully lower the motor while disconnect-
ing the drain hose.
Installation is a reversal of the removal procedure
with attention to the following points:
( t ) Tighten all bolts securely.
(2) Check that the blow er fan operates correctly.
Dismantled view of the blower fan and associated
components.
12. AIR CONDITIONING
DESCRIPTION
The air conditioning system, when used in con-
junction with the heater, enables any reasonable tem-
perature to be achieved inside the vehicle. It can also
reduce the humidity of the incoming air, aiding
demisting even when cooling is not required.
The basic components of the air conditioning sys-
tem are an evaporator, co ndenser, compressor, re-
ceiver/dryer, expansion valve and pipes and hoses
carrying the refrigerant through the system. Various
subsidiary controls and sensors are also utilized to
protect the system against low or high pressure and
excessive temperature.
The refrigerant will boil at a very low tempera-
ture (-33 deg C) and therefore must be contained
under pressure. Escaping refrigerant can cause frost-
bite and eye damage and will produce a poisonous gas
when burnt. Also, if the system suffers a rapid loss of
refrigerant, oil from the compressor may be carried
out with the refrigerant. It is recommended that any
work requiring disconnection of the components be
referred to an au thorized dealer.
In the event of major repair s to the vehicle such as
engine removal, the compress or hoses are of sufficient
Schematic diagram of a typical air conditioning
system.
length to allow the compressor to be removed as the
engine is lowered from the engine compartment with-
out disturbing any refrigerant line connections.
If the operation of the air conditioning system is
in doubt, it is recommended that the vehicle be taken
to an authorized dealer for testing and repair.
TO CHECK REFRIGERANT CHARGE
(1) Start the engine and operate the air condi-
tioner on maximum cooling for a few minutes.
(2) Observe the flow of refrigerant through the
sight glass located at the top of the receiver/dryer. On
some models it may be necessary to use a mirror to
see the sight glass. (3) If the system is operating correctly, the sight
glass will be clear during the operation of the com-
pressor. Occasional bubbles may be seen when the
compressor cycles on and off during operation, but a
NUT j-
Bubbles in the sight glass when the air conditioner is
operating indicates a low refrigerant charge.
Page 82 of 238
82
FUEL AND ENGINE MANAGEMENT
CAUTION: To prevent severe electrical shock, extreme care must be taken when
working on or near the electronic ignition system as dangerous high tension voltages
are produced in both the primary and secondary circuits. See the text fo\
r
precautionary notes.
SPECIFICATIONS
FUEL INJECTION
Type:
1.6 liter engine .................................. Single point
1.8 liter engine................................... Multi point
FUEL PUMP
Type ................................................................ Electric
Pressure at idle:
1.6 liter engine ..................................... 62-90 kPa
1.8 liter engine ................................ 190-230 kPa
FUEL FILTER
Type ................................................ Inline, disposable
AIR FILTER
Type ................................... Disposable paper element
DISTRIBUTOR
Make ........................................................ Delco Remy
Advance contro l .......................................... Electronic
Rotation of rotor .................................. Anti-clockwise
Firing order....................................................1 -3-4-2
ADJUSTMENTS
Base idle speed ..................................... 550-650 rpm
Ignition timing.......................................... 10° BTDC
TORQUE WRENCH SETTINGS
Throttle body nuts.......................................... 10 Nm
*Throttle body bolts ........................................ 12 Nm
*Fuel hose fittings............................................ 35 Nm
Fuel rail bolts ....................................................8 Nm
Fuel tank drain plug ........................................ 24 Nm
Coolant temperature sensor ............................ 12 Nm
Oxygen sensor .................................................. 40 Nm
MAT sensor..................................................... 14 Nm
*1.6 liter engine
l . 8 liter engine
1. FUEL AND ENGINE MANAGEMENT
TROUBLE SHOOTING
NOTE: The following Trouble Shooting pro-
cedures are basic checks only. If these pro-
cedures fail to locate the fault, refer to the
System Diagnosis and Adjustments heading
for more thorough testing.
Prior to performing any of the following
operations, refer to the Service Precautions
and Procedures heading.
ENGINE WILL NOT START OR HARD TO
START
(1) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter.
(2) Fault in the power supply: Check the battery,
fusible links and fuses. Check for clean, secure con-
nections, particularly the earth connections. Check the
EG1 and fuel pump relays.
NOTE: If the fuel pump relay fails, power
will be supplied to the fuel pump via the oil
pressure switch. When starting the engine,
Check that the MAP sensor hose is not blocked or split
and ensure that all electrical connections are clean and
secure.
Page 83 of 238
Fuel and Engine Management 83
the fuel pump will not operate until the oil
pressure is sufficient to extinguish the oil
pressure warning lamp. Therefore it will be
necessary to operate the starter motor for a
longer period than usual to start the engine.
(3) Faulty EFI component wiring connections:
Check that all component wiring connections are
clean and secure.
(4) Manifold absolute pressure (MAP) sensor
vacuum hose blocked or disconnected: Clear or recon-
nect the vacuum hose. (5) Fault in the ignition system: Check the
primary and secondary ignition circuits.
(6) Engine flooded: Fully depress the throttle
pedal until the engine starts. Check the coolant
temperature sensor. Check th e injector(s) for leakage.
ENGINE STARTS THEN STALLS
(1) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter.
(2) Air leakage at the inlet manifold: Check all
joints and hoses for air leaks. (3) Faulty EFI wiring connections: Check that
all component wiring connections are clean and
secure.
(4) Ignition timing incorrectly set: Check and
adjust the timing. (5) MAP sensor faulty or supply hose discon-
nected or blocked: Check the vacuum supply hose.
Check the operation of the MAP sensor.
ENGINE MISFIRES
(1) Faulty, dirty or incorrectly adjusted spark
plugs: Renew or clean and adjust the spark plugs.
(2) Condensation in the distributor cap: Dry and
examine the cap for cracks. (3) Faulty high tension leads: Check and renew
the high tension leads.
Testing the fuel system pressure using a pressure
gauge.
(4) Faulty ignition coil: Check and renew the
ignition coil.
(5) Fuel blockage: Check for blockage in the fuel
filter, lines and injector(s). (6) Low fuel pressure: Check the fuel pump and
fuel pressure regulator. (7) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter. (8) Loose fuel supply wiring connectors: Check
all connectors for tightness. (9) Faulty fuel injector: Check the connections
and test the condition of the fuel injectors.
ENGINE LACKS POWER
(1) Ignition timing incorrectly set: Check and
adjust the timing.
(2) Water in the fuel: Dr ain the fuel from the
system and renew the fuel filter.
(3) Incorrectly adjusted throttle cable: Adjust the
throttle cable.
Check the distributor cap for cracks or tracking be- tween the terminals. The air filter element should be renewed at 40 000 km
intervals. 1.8 liter engine.
Page 84 of 238
Fuel and Engine Management
(4) MAP sensor faulty or supply hose discon-
nected or blocked: Check the vacuum supply hose.
Check the operation of the MAP sensor.
EXCESSIVE FUEL CONSUMPTION
(1) Blocked air cleaner element: Check the ele-
ment and clean or renew as necessary.
(2) Incorrect fuel pressure: Check the fuel pump
and fuel pressure regulator. (3) Faulty coolant temperature sensor: Check
the connections and operation.
(4) Leaks in the fuel supply system: Check the
connections and components for leakage. (5) Leaking fuel injector(s): Clean or renew the
faulty injector(s). (6) Engine operating temperature too low:
Check the thermostat and electric cooling fan as
described in the Cooling an d Heating Systems section.
2. DESCRIPTION
The engine management system on the range of
vehicles covered by this manual controls the opera-
tion of the ignition system and the fuel system.
The central component of the engine management
system is the electronic control unit (ECU). The con-
trol unit is a micro-computer which controls the igni-
tion timing and the amount of fuel injected according
to signals received from various sensors. As changes
are detected in engine load and speed, coolant tem-
perature, barometric pressure, air temperature (1.8
liter engine), throttle position and vehicle speed, the
control unit alters the ignition timing and the fuel
injection amount to achieve optimum engine effi-
ciency.
The control unit incorporates a self diagnosis
mode which stores and displays codes relating to
certain system malfunctions. Whenever power is sup-
plied to the control unit, the control unit performs a
View of the 1.8 liter engine showing the engine management components.
Ensure that all fuel connections are securely tightened.
Page 86 of 238
86 Fuel and Engine Management
other. The fuel pressure is maintained at a constant
pressure relevant to the manifold vacuum. A dispos-
able paper element fuel filter is mounted on the engine
bulkhead.
The amount of fuel injected is relevant to the time
the injector remains open. The basic time the injector
remains open is governed by the control unit which
uses information from the various sensors to give
optimum engine efficiency for given conditions.
The idle air control (IAC) valve controls the fast
idle speed during engine warm up and maintains the
basic idle speed at a set value by compensating for
loads such as air conditioning or the selection of Drive
on automatic transaxle models.
The throttle body assembly is mounted to the
inlet manifold and controls the amount of air entering
the engine by the action of the throttle valve.
Efficient operation of the EFI system depends on
accurate signals being receiv ed by the control unit and
controlled air flow beyond the throttle valve. There-
fore it is essential that all air, fuel and electrical
connections be clean and tight.
3. SERVICE PRECAUTIONS AND
PROCEDURES
Electronic ignition systems can produce danger-
ously high voltages in both the primary and secondary
circuits. For this reason, extreme care must be taken
when working on or near the ignition system.
Do not start the engine if the battery terminals are
not clean and tight.
Do not use the fast charge or boost settings on a
battery charger to start the engine.
Do not disconnect the battery terminals while the
engine is running.
Disconnect the battery terminals before charging
the battery.
Disconnect the negative ba ttery terminal before
working on the engine management system.
Do not subject the control unit to temperatures
above 80 deg C.
Ensure that all wiring connectors are clean and
tight.
Disconnect the battery terminals and the control
unit wiring connectors before attempting any welding
operations.
Do not direct a steam cleaning or pressure
washing nozzle at engine management components
when cleaning the engine.
Ensure that the ignition is Off prior to disconnect-
ing the battery terminals, fusible links or the control
unit wiring connectors.
TO CONNECT ELECTRICAL TEST
EQUIPMENT
NOTE: Some types of tachometers, timing
lights and ignition system analysers are not
compatible with this engine management
system and may result in incorrect readings.
It is therefore recommended that the man-
ufacturer of the lest equipment be consulted
before proceeding to use the equipment.
If a test procedure requires the use of a
test lamp or voltmeter, ensure that only the
specified instrument is used to prevent mis-
leading diagnosis.
MULTIMETER
It is essential that in all tests where voltage or
resistance is to be measur ed, a digital display multi-
meter with a minimum 10 megohms impedance be
used.
The correct method of backprobing the wiring connec-
tors. The meter test probe should be modified with a piece of thin wire as shown.
All meter readings are to be performed with the
component wiring connectors installed unless other-
wise instructed. This can be done by inserting the
meter test probes from the wiring harness side of the
connector or backprobing. If the test probes are not
thin, they should be modified by attaching a thin piece
of wire to the end, giving a fine point that will not
damage the connector. Ensure that the wire is making
good contact with the probe.
If sealing plugs or boots are removed from wiring
connectors to facilitate bac kprobing, ensure that they
are correctly installed at the conclusion of the test
procedure.
To identify wiring connector terminals refer to the
wiring circuit diagrams.
Test Lamp
To avoid damage to the electronic components
when testing, the use of an LED (light emitting diode)
test lamp is recommended.
Page 90 of 238
90 Fuel and Engine Management
To identify the code number, count the number of
times the ECM warning lamp flashes. Each fault code
comprises two groups of flashes separated by a 1.2
second pause. The first group represents tens and the
second group represents single units. For example 1
flash followed by a 1.2 second pause followed by 4
flashes would be code number 14. Similarly 4 flashes
followed by a 1.2 second pause followed by 2 flashes
would be code number 42.
The code will be displayed three times. If more
than one fault code is present, the self diagnosis
system will indicate each one in numerical order, with
a 3.2 second pause between each code, and then
repeat the sequence.
The fault codes can be identified as follows:
CODE NUMBER FAULT AREA
12 Satisfactory operation
13 Oxygen sensor open circuit
14 Coolant temperature sensor circuit (voltage low)
15 Coolant temperature sensor circuit (voltage high)
21 Throttle position sensor circuit (voltage high)
22Throttle position sensor circuit (voltage low)
23MAT sensor circuit (voltage' high) 1.8 liter engine
only
24 Vehicle speed sensor circuit
25 MAT sensor circuit
(voltage low) 1.8 liter engine
only
33 MAP sensor circuit
(voltage high)
34MAP sensor circuit (voltage low)
42 Electronic spark timing circuit
44
Oxygen sensor circuit
(lean exhaust)
45Oxygen sensor circuit (rich exhaust)
51 Mem-Cal
55 Control unit input circuits
Test Procedure
(1) Perform the following checks:
(a) Ensure that the battery voltage is above 11
volts. (b) Ensure that the throttle valve is fully closed.
(c) Place the transaxle in neutral.
(d) Ensure that the air conditioner, fan, tights
and all other accessories are switched off.
(2) Turn the ignition On and confirm that the
ECM warning lamp on the instrument cluster is
illuminated but not flashing.
If code 55 is displayed, refer to the Control Unit
heading, perform the circuit test procedure and rectify
the cause of the code before proceeding.
If the ECM warning lamp flashes codes other than
code 55, check the wiring harness between the diag-
nostic link connector terminal B and the control unit
wiring connector terminal A9 for shorts. Repair or
renew the wiring harness as necessary.
If no fault can be found, renew the control unit.
If the ECM warning lamp does not illuminate,
proceed as follows:
(a) Check the METER fuse located in the fuse
panel adjacent to the steering column and the fusible
links located in the fusible link connecting block at the
rear of the battery. Renew the fuse or fusible links as
necessary. (b) Check the wiring harness to the instrument
cluster. Repair or renew the harness. (c) Check the Check Engine lamp bulb. Renew if
necessary. (d) Check the EGI relay. Renew as necessary.
(3) Connect a jumper lead across terminals A
and B on the diagnostic link connector located under
the front passengers seat above the control unit.
(4) Note the codes indicated by the flashing
ECM warning lamp.
If code 12 is displayed, the system is operating
correctly.
If codes other than code 12 are displayed, refer to
the component or circuit test procedure under the
appropriate heading as indicated by the code number.
If more than one code is being displayed, test each
indicated fault working in the order of display of the
code numbers.
(5) After completing the self diagnosis test pro-
cedure, remove the jumper lead from the diagnostic
link connector. (6) After repairing or renewing the necessary
View showing the location of the diagnostic link
connector. Passengers seat removed for clarity.
Inset shows the diagnostic link connector terminal identification.
Page 99 of 238
Fuel and Engine Management 99
stalled on each side of the air cleaner mounting
bracket when installing the mounting bolts.
(2) If renewing the element, ensure that the
specified element is installed and is correctly seated in
the air cleaner housing. (3) Ensure that the air intake hose clamps are
tightened securely.
To Remove and Install — 1.6 Liter Engine
(1) Disconnect the negative battery terminal.
(2) Remove the nuts and washers retaining the
air cleaner to the throttle body assembly. (3) Release the top cover retaining clips and
remove the top cover and the air cleaner element.
Remove the air cleaner retainer from the throttle body
bolts. (4) Disconnect the engine vent hose from the air
cleaner support clamp. (5) Slightly raise the air cleaner and tilt it
towards the windscreen. Disc onnect the engine vent
hose and the temperature sensor vacuum hose from
the underside of the air cleaner. (6) Remove the air cleaner housing from the
engine.
Dismantled view of the air cleaner.
(7) Thoroughly clean the air cleaner housing and
top cover and check for cracks or damage that would
allow unfiltered air to enter the engine. Renew any
components as necessary.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Inspect the air cleaner base gasket. Renew if
necessary. (2) Connect the engine vent hose and the tem-
perature sensor vacuum hose. (3) Install the air cleaner ensuring that the hot air
inlet tube is located correc tly between the exhaust heat
shield and the air cleaner housing. (4) When installing the top cover retaining nuts,
hand tighten only. THROTTLE BODY ASSEMBLY
To Remove and Install — 1.8 Liter Engine
(1)
Disconnect the negative battery terminal.
(2) Release the air intake hose clamp and dis-
connect the air intake hose from the throttle body. (3) Unclip the actuating rod from the throttle
lever using a small screwdriver under the ball socket if
necessary.
(4) Mark the throttle body vacuum hoses with
quick drying paint or similar and disconnect the hoses
from the throttle body. Disconnect the engine vent
hose from the throttle body. (5) Disconnect the wiring connectors from the
throttle position sensor and the IAC valve.
(6) Remove the retaining nuts and withdraw the
throttle body and gasket.
View of the throttle body and actuating rod. The rod
length must be set so that dimension A - 8—9 mm for
automatic transaxle models and 3—4 mm for manual
transaxle models.
View of the throttle body and associated components.
Page 100 of 238
100 Fuel and Engine Management
Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure that all throttle body passages are
clean. Blow out with compressed air if necessary. (2) Install the throttle body to the inlet
manifold
using a new gasket and tighten the retaining nuts to
the specified torque. (3) Connect the vacuum hoses to the throttle
body in the positions previously marked. (4) Clip the actuating rod to the throttle body
lever. Check the dimensions shown in the illustration
and adjust the rod length if necessary.
(5) Check the adjustment of the throttle cable as
described later in this section.
(6) Connect the air intake hose and tighten the
hose clamps securely.
To Remove and Install — 1.6 Liter Engine
(1) Depressurize the fuel system as previously
described. (2) Disconnect the negative battery terminal.
(3) Remove the air cleane r assembly and base
gasket as previously described. (4) Mark the fuel supply and return hoses,
release the clamps and disconnect the hoses from the
throttle body assembly. (5) Disconnect the injector, throttle position
sensor and the IAC valve wiring connectors. Remove
the injector wiring harness from the throttle body
assembly and place it to one side.
(6) Mark and disconnect the vacuum hoses from
the throttle body assembly. (7) On automatic transaxle models, disconnect
the kickdown actuating rod from the throttle linkage.
(8) Slide the outer throttle cable from the
mounting bracket, rotate the throttle linkage and disconnect the inner throttle cable from the throttle
linkage.
(9)
Remove the bolts retaining the throttle body
assembly to the inlet manifold and remove the
assembly and the gasket from the engine. (10) If necessary remove the retaining screws and
remove the fuel meter assembly, the IAC valve and
the throttle position sensor from the throttle body
assembly. Installation is a reversal of the removal procedure
with attention to the following points:
(1) If removed, install the fuel meter assembly,
the throttle position sensor and the IAC valve as
described under the relevant headings. (2) Install the throttle body assembly to the inlet
manifold using a new gasket and tighten the retaining
bolts to the specified torque. (3) Connect the vacuum ho ses to the throttle
body using the marks made on removal to ensure
correct installation. (4) On automatic transaxle models, connect the
kickdown actuating rod to the throttle linkage.
(5) Install the throttle cable and check the adjust-
ment as described later in this section.
INLET MANIFOLD
To Remove and Install
To remove and install the inlet manifold, refer to
the relevant heading in the Engine section.
IDLE AIR CONTROL (IAC) VALVE
To Test
(1) Connect an accurate tachometer to the en-
gine. (2) With the engine at normal operating temper-
ature and all accessories switched Off, note the idle
speed.
(3) With the ignition switched Off, disconnect
the IAC valve wiring connector. (4) Start the engine and check the idle speed.
If the idle speed is the same as that noted in
operation (2) proceed to operation (7).
If the idle speed is higher than noted in operation
(2) proceed as follows.
(5) With the ignition switched Off, connect the
IAC valve wiring connector.
(6) Start the engine and check the idle speed.
If the idle speed is not the same as that noted in
operation (2) proceed to operation (7).
If the idle speed is the same as noted in operation
(2) the IAC valve is operating correctly. However, if
the engine is not idling correctly carry out the
following checks.
(a) Check the air inlet system for vacuum leaks.
NOTE: Any vacuum leak will cause a fast
idle.
View of the throttle body assembly showing the loca-
tion of the base idle adjusting screw. 1.8 literengine.
Page 101 of 238
Fuel and Engine Management 101
Location of the idle air control (IAC) valve. Inset shows the terminal identification.
(b) Check for a binding throttle cable, throttle
shaft or throttle position sensor. (c) Check the coolant temperature sensor resis-
tance as described later in this section. (d) Ensure that the battery terminals and the
engine earth terminals are clean and secure.
(e) Check the operation of the Park/Neutral
switch and the transaxle as described in the Automatic
Transaxle section under the Neutral Safety Switch
heading. (f) Check the spark plug gaps as described in the
Engine Tune-up section.
(g) Check the base idle speed adjustment.
(h) Check the fuel pressure and check the system
for leaks as described previously.
(I) Check the alternator voltage output as de-
scribed in the Electrical System section to ensure that
it is between 9-17 volts.
(j) Remove the IAC valve and check the bore in
the throttle body for dirt or damage.
(7) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. (8) Disconnect the wiring connector from the
IAC valve.
(9) Check for voltage at each of the terminals on
the IAC valve wiring connector using a test lamp. If the test lamp flashes at each terminal, correct
operation of the wiring and control unit is indicated.
check for faulty IAC valve terminals. If no fault is
found renew the IAC valve.
If the test lamp is a steady light at one or more
terminals, proceed to operation (10).
If the test lamp does not flash at one or more of
the terminals proceed as follows:
(a) Check the circuit with no voltage for shorts
and for continuity between the IAC valve and the
control unit. Repair or renew the wiring harness as
necessary.
(b) Measure the resistance across the IAC valve
terminals A and B, and across terminals C and D. The resistance should be more than 30 ohms.
If the resistance is not as specified, renew the IAC
valve.
If the resistance is as specified, check for faulty
wiring connector terminals on the IAC valve and the
control unit. If no fault is found, renew the control
unit
(10) Switch the ignition Oft' and disconnect the
control unit wiring connectors. (11) Switch the ignition On and check the IAC
connector with the test lamp again. If the light is stilt
steady on one or more terminals there is a short
circuit to voltage in the wiring harness. Repair or
renew as necessary. (12) If the light is not on, check for faulty IAC
valve terminals. If no fault is found renew the IAC
valve.
To Remove and Install
(1) Disconnect the negative battery terminal.
(2) On 1.6 liter engines, remove the air cleaner
assembly as previously described. (3) Disconnect the wiring connector from the
IAC valve. (4) Remove the IAC valve retaining screws and
withdraw the IAC valve and O ring.
View of the IAC valve removed from the throttle body
assembly. 1.6 liter engine.
(5) Clean the IAC sealing surfaces to ensure
proper operation.
Installation is a reversal of the removal procedure
with attention to the following points:
(1) When installing a new IAC valve ensure that
the part number is correct as the valve is not
interchangeable between the 1.8 and 1.6 liter engines.
(2) Measure the length of the pintle extension as
shown in the illustration. If necessary push the pintle
in by exerting firm thum b pressure with a slight
rocking motion.
NOTE: Installing (he IAC valve with the
pintle protruding too far can damage the
valve.