air fuel meter NISSAN PULSAR 1987 Workshop Manual
[x] Cancel search | Manufacturer: NISSAN, Model Year: 1987, Model line: PULSAR, Model: NISSAN PULSAR 1987Pages: 238, PDF Size: 28.91 MB
Page 11 of 238
General Information 11
Lifting Equipment
When using lifting equipment to lift heavy com-
ponents such as the engine and/or transmission, use
metal slings or chain in preference to rope. If rope
must be used, ensure that it is not placed against sharp
edges on the component.
Automotive Lubricants and Solvents
Avoid prolonged skin contact with oils, greases
and solvents as some can cause skin irritations and
dermatitis.
Exercise caution when us ing cleaning solvents as
many are inflammable. Do not smoke. Keep naked
flames and sparks clear of the work area.
Compressed Air
Never point an air hose at another person or allow
compressed air to blow onto your skin. High pressure
air forced against the skin can enter the bloodstream
and prove fatal.
Suspension and Steering Components
Damaged suspension and steering components
should not be welded. Many of these components are
fabricated from toughened metals. If welded they may
lose their strength or become brittle. Damaged com-
ponents should be renewed.
Air Conditioning
Avoid disconnecting air conditioning hoses as
escaping refrigerant can cause frostbite. The refriger-
ant is highly flammable and when burnt, a poisonous
gas is produced.
VEHICLE SAFETY
To prevent damage to the vehicle during servicing
or repair work, note the following precautions.
Brake Fluid
If spilt on the vehicle paintwork, brake fluid
should be immediately washed away with clean water
and allowed to dry naturally, not wiped with a cloth.
Catalytic Converter
The following should be observed to prevent
damage to the catalytic converter:
Do not operate the vehicle on leaded fuel.
Do not push or tow start the vehicle.
Do not allow the engine to idle for prolonged
periods.
Do not switch the ignition off while the vehicle is
in motion and the transmission is in gear.
Do not 'prime' the engine by pouring fuel into the
inlet manifold.
Do not operate the vehicle if the engine is
misfiring.
Avoid running the vehicle out of fuel.
Ensure that the engine oil is formulated to contain
low phosphorus levels.
Electronic Components
The electronic components of the ignition and
fuel injection systems can be damaged by the use of
incorrect testing equipment.
It is essential in all tests where voltage or resis-
tance is to be measured that a digital display multi-
meter with a minimum 10 megohm input impedance
be used.
Some types of tachometers, timing lights and
ignition system analyzers are not compatible with
certain engine electronic systems. It is therefore
recommended that the manufacturer of the test equip-
ment be consulted before using the equipment.
Jump starting, or being jump started by another
vehicle can cause damage to the electronic compon-
ents of the vehicle. Refer to the Roadside Trouble
shooting section for the correct jump starting proce-
dure.
3. GENERAL REPAIR PROCEDURES
SEIZED FASTENERS
Seized bolts, nuts or screws should first have a
liberal amount of penetrating oil applied. The fastener
should be left for a period of time to allow the oil to
penetrate and soften the corrosion which is causing
the binding.
Often, a sharp hammer blow to the head of the
fastener can dislodge the corrosion and permit it to be
loosened.
An impact driver, which can be fitted with a
socket or screwdriver bit, can be used to loosen a
seized fastener.
Another method is to heat the component in
which the fastener is seized. However, extreme cau-
tion should be exercised when heating aluminum
alloy components as the melting point is much lower
than that of steel.
If the above methods fail to free a seized nut,
carefully hacksaw through one side of the nut until it
can be split. Care should be taken that the threads of
the bolt or stud are not damaged.
Should a bolt or stud break below the surface of
the component, it will be necessary to use a screw
extractor to remove the remaining part. Follow the
screw extractor manuf acturers instructions.
Tap and die set and assorted screw extractors.
Page 29 of 238
Engine Tune-up 29
Check the cylinder compressions using a compression gauge.
(a) Inject a small amount of engine oil into the
spark plug hole of the cylinder concerned ensuring
that the oil is evenly distributed within the cylinder by
rotating the engine.
(b) Repeat the compression test on the cylinder
concerned.
A substantial increase of compression pressure
indicates faulty or worn piston rings, pistons or
cylinder.
No increase of compression pressure indicates
burnt, obstructed or sticking valves, or a leaking or
blown cylinder head gasket.
(9) Install the fusible li nk and connect the high
tension lead to the coil.
TO SERVICE THE DISTRIBUTOR
The electronic ignition system requires virtually
no maintenance except for checking of the distributor
cap. rotor and high tension leads as described below.
Refer to the Fuel and Engine Management section
for Specifications and Trouble Shooting.
NOTE: When working on or near electronic
ignition systems, care should be taken as
dangerous high voltages are present in both
the primary and secondary circuits.
The ignition switch should be turned off
before removing or inst alling any electrical
connections otherwise damage to the igni-
tion system as well as severe electrical shock
could result.
TO SERVICE HIGH TENSION LEADS
Check the leads for perishing or cracking and
renew as required. Never a ttempt to repair defective
carbon impregnated core leads.
The lead may be carefully cleaned, using cloth
moistened with kerosene a nd then wiped completely
dry.
If an ohmmeter is available the electrical resis-
tance of the leads may be checked as follows:
View showing the location of the fusible links.
Check the spark plug high tension leads for cracks and
burnt or corroded terminals.
Check the distributor cap for cracks or tracking
between the terminals
.
Page 42 of 238
42 Engine
The cylinder block is a cast iron alloy, deep skirt
design and the crankshaft is supported in the cylinder
block by five precision insert replaceable main bear-
ings. Crankshaft end float is controlled by the flanged
centre main bearing. Connecting rods are I section
forgings equipped with precision insert replaceable big
end bearings. The gudgeon pins are an interference fit
in the connecting rod and a floating fit in the piston.
The cast aluminum pistons are equipped with
two compression rings and one oil control ring.
The twin rotor, involute gear oil pump is mounted
directly to the front face of the cylinder block. The
inner rotor is internally driven by the crankshaft. The
oil pump pressure relief valve is not adjustable, and
consists of a plunger and spring mounted in the oil
pump body.
The pump draws oil through a screen in the sump
and delivers it, via a full flow replaceable oil filter, to
the oil gallery from where it is distributed to the
hydraulic tappets, camshaft and crankshaft bearings
and to the overhead rocker and valve mechanism.
3. ENGINE AND TRANSAXLE ASSEMBLY
Special Equipment Required:
To Remove and Instill — Suitable lifting tackle,
extra long chassis stands, suitable trolley
TO REMOVE
NOTE: Due to the high residual pressure
within the fuel system, it will be necessary to
depressurize the system before removing any
fuel supply components. Refer to the Fuel
and Engine Management section for the
correct procedure.
(1) Disconnect the negative battery terminal.
(2) Mark around the bonnet hinges with a soft
lead pencil Co facilitate correct installation. With the
aid of an assistant, remove the bonnet retaining bolts
and remove the bonnet from the vehicle.
(3) Drain the engine and transaxle lubricant.
(4) Open the coolant drain tap located on the
lower radiator pipe and drain the coolant. (5) Loosen the hose clips and disconnect the
heater hoses from the heater pipes at the bulkhead.
NOTE: Do not use excessive force to remove
the heater hoses from the heater pipes or the
heater core will become dislodged from the
heater unit. If necessary, cut the heater
hoses from the pipes using a sharp knife.
(6) Loosen the hose clamps and disconnect the
radiator hoses from the engine assembly. (7) Disconnect the positive lead from the bat-
tery. (8) On 1.8 liter models, disconnect the air inlet
duct.
(9) On 1.6 liter models, remove the air cleaner
assembly. Refer to the Fuel and Engine Management
section if necessary. (10) Disconnect the throttle cable from the throt-
tle body and from the camshaft housing top cover
bracket, if applicable. (11) Disconnect the fuel supply and return hoses.
Mark the hoses as an aid to installation. (12) Suitably mark and disconnect the charcoal
canister hoses. (13) Disconnect the injector wires from the injec-
tors. On 1.6 liter models, slide the wiring out from the
throttle body. (14) Disconnect the wiring fr om the throttle po-
sition sensor (TPS), idle air control (IAC) valve,
oxygen (O
2) sensor wire, coolant temperature sensor,
coolant sender and on 1.8 liter models, the manifold
air temperature (MAT) sensor. (15) Disconnect the wiring connector adjacent to
the top heater hose, the wiring from the alternator and
the two earth wires from underneath the cylinder head
bolts. (16) Lay the wiring loom over on the passenger
side of the engine compar tment, clear of the work
area.
(17) On manual transaxle models, loosen the
clutch cable adjusting nuts and remove the cable
through the slot in the lever. Remove the clutch cable
bracket from the transaxle after removing the retain-
ing bolts and place the cable to one side.
(18) Disconnect the wiring from the starter mo-
tor, speedometer sender and on manual transaxle
models, the reverse lamp switch wiring.
(19) If applicable, disconnect the power steering
lines from the pump and drain the fluid into a
container. Suitably plug the lines and the pump to
prevent the entry of dirt.
(20) On automatic transaxle models, disconnect
the selector cable and bracket from the transaxle
assembly.
Disconnect the transaxle oil cooler lines from the
transaxle. Plug the lines and fittings to prevent the
entry of dirt etc.
(21) Loosen the front wheel nuts, raise the front
of the vehicle and support it on extra long chassis
stands. Ensure that the vehicle is high enough to allow
removal of the engine from underneath. (22) Remove the front wheels and the engine
splash guards from the vehicle.
(23) On manual transaxle models, remove the
stay rod and control rod bolts and nuts and disconnect
the rods from the transaxle.
(24) Remove the lower control arm to steering
knuckle ball joint nuts and separate the ball joints
from the steering knuckle by holding a dolly or a
hammer against one side of the steering knuckle and
hitting the other side with a hammer. The taper on the
ball joint will release fr om the steering knuckle.
(25) Pull the steering knuckles outward swiftly to
Page 48 of 238
48 Engine
TO INSTAL
(1) Check that the camshaft and crankshaft
timing gears have not been moved and that the timing
marks are still aligned. It will be necessary to tempo-
rarily install the crankshaft pulley to check that the
timing marks are still aligned. (2) Install the drive belt to the crankshaft timing
gear around the water pump gear and onto the
camshaft timing gear.
NOTE: If the original drive belt is being
installed, ensure that the arrow marked on
the belt prior to removal is pointing in the
direction of rotation.
(3) Use the adjusting tool to turn the water
pump assembly sufficiently to engage the water pump
pulley with the drive belt. (4) Install the inner cover lower retaining bolt.
(5) Ensure that the drive be lt is correctly meshed
with the teeth of the camshaft, crankshaft and water
pump gears. Install the crankshaft pulley and tighten
the bolts to Specifications. (6) Adjust the drive belt as described under the
following heading.
(7) Install the drive belt outer cover and fasten
the retaining clips. (8) Install and adjust the alternator and if
equipped, the power steeri ng and air conditioning
drive belts as desc ribed in the Engine Tune-up section.
TO ADJUST
(1) Remove the alternator drive belt and if
equipped, the power steering and air conditioning
drive belts. (2) Release the clips securing the camshaft drive
belt outer cover to the inner cover and remove the
outer cover. (3) Turn the engine in the direction of rotation
until the timing marks on the camshaft and the inner
cover are aligned. (4) Loosen the water pump retaining bolts and
using the adjusting tool, rotate the water pump
housing to gain the required belt tension. The belt is
correctly tensioned when it can be grasped between
the thumb and forefinger midway between the cam-
shaft timing gear and the water pump gear and turned
ninety degrees from i t s operating position.
After the belt has been tensioned, tighten the
water pump retaining bolts to the specified torque.
NOTE: Over tensioning of the drive belt will
result in noisy operation and premature
wear of the belt.
(6) Install the outer drive belt cover.
(7) Install and adjust the alternator, and if
equipped, the power steering and air conditioning
drive belts as desc ribed in the Engine Tune-up section. 6. CAMSHAFT. ROCKER ARMS AND TAPPETS
Special Equipment Required:
To Check Camshaft — Dial gauge, Vee blocks and
micrometers
To Install — Drive belt adjusting tool
It is recommended that a new cylinder head
gasket is installed and the cylinder head bolts renewed
when the camshaft housing is removed.
TO REMOVE
(1) Disconnect the negative battery terminal.
Remove the nuts securing the earth wires to the
cylinder head bolts and remove the earth wires.
(2) On 1.6 liter models, remove the air cleaner
wingnuts and withdraw the air cleaner.
(3) Disconnect the engine breather hoses from
the camshaft housing and the camshaft housing top
cover. (4) Remove the camshaft housing top cover
retaining bolts and remove the top cover. Discard the
gasket.
(5) Remove the camshaft dr ive belt as described
under the previous heading. (6) Using an open ended spanner, hold the
camshaft between the inle t and exhaust lobes of
number four cylinder and remove the camshaft timing
gear retaining bolt and the camshaft timing gear.
(7) Remove the distributor, distributor cap and
high tension leads. If necessary refer to the Fuel and
Engine Management section. (8) Check the camshaft end float before remov-
ing the camshaft from the engine. Mount a dial gauge
to the cylinder block with the plunger bearing on the
distributor drive end of the camshaft. (9) Lever the camshaft towards the dial gauge
and zero the gauge. Move the camshaft in the opposite
direction away from the dial gauge and note the
reading obtained. Check this measurement against
Specifications.
Checking the camshaft end float.
Page 75 of 238
Cooling and Heating Systems 75
(4) Remove the bolts retaining the fan shroud
assembly to the radiator and carefully move the
shroud assembly upwards and towards the engine to
release it from the lower mountings.
NOTE: On models with air conditioning, it
will be necessary to hold the air conditioning
compressor hoses toward s the engine to
allow clearance for removal of the shroud
assembly.
(5) If necessary, remove the fan from the fan
motor by removing the retaining bolts or on some
models the nut and washers.
(6) If necessary, remove the fan motor from the
shroud assembly by removing the retaining bolts or
nuts. Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure all the fan motor and fan retaining
nuts and bolts are tightened securely. (2) Ensure that all the rubber mountings are in
good condition. Installation is a reversal of the removal procedure
with attention to the following points:
(1) Ensure that all sealing surfaces are clean.
(2) Renew the O ring on installation.
(3) Tighten the thermostat cover retaining bolts
securely.
(4) Fill the cooling system as previously de-
scribed ensuring that the heater control lever is in the
maximum heat position. Check for coolant leaks.
TO CHECK
NOTE: A visual examination of the thermo-
stat will often determine its serviceability
and make further testing unnecessary. For
instance, a thermostat with its valve fully-
open when removed from a cold engine is
obviously faulty and should be renewed.
Remove the thermostat from the thermostat
6. THERMOSTAT
Special Equipment Required:
To Check — Thermometer
TO REMOVE AND INSTAL
(1) Drain the cooling system as previously de-
scribed under the Radiator heading.
(2) On 1.6 liter models, remove the air cleaner
assembly. Refer to the Fuel and Engine Management
section if necessary. (3) Disconnect the top radiator hose from the
thermostat cover.
(4) Remove the bolts retaining the thermostat
cover to the thermostat housing. (5) Remove the thermostat cover, thermostat
and O ring from the thermostat housing.
NOTE: The thermostat and cover are ser-
viced as a unit and cannot be renewed
separately.
View of the thermostat removed from the vehicle and dismantled for testing. Line drawing showing the correct method to test the
thermostat.
(4) Progressively heat the mixture noting the
temperature reading on the thermometer as the ther-
mostat valve commences to open and when it is fully
open.
See the Specifications for opening and fully open
temperatures.
A thermostat which is not opening or is not open
at the specified temperatures should be renewed.
Page 85 of 238
Fuel and Engine Management 85
View of the 1.6 liter engine showing the engine management components. Air cleaner removed for clarity.
series of tests on various components in the system
and records the results, If a fault is discovered, the
ECM warning lamp on the instrument cluster will
illuminate while the engine is running. When the self
diagnosis mode is activated, the ECM warning lamp
will flash codes indicating the area in which the fault
has occurred.
This function is very useful in locating system
faults, particularly intermittent problems. However,
the self diagnosis mode does not provide comprehen-
sive testing of the EFI system, and therefore should
always be used in conjunction with the other test
procedures described later in this section in order to
accurately locate system faults.
The high energy electronic ignition system con-
sists of a distributor and an ignition coil.
The distributor has two functions. The first is to
produce and distribute secondary high tension voltage
to the spark plugs.
The second function is to provide the control unit
with information on engine speed and crankshaft
position.
The ignition timing is constantly adjusted by the
control unit to suit varying engine and vehicle oper-
ating conditions.
In the fuel injection system, a metered amount of
fuel is sprayed into the air stream. The air/fuel
mixture then enters the combustion chamber via the
inlet valves.
On 1.6 liter engines, the fuel is injected by a single
injector, located above the throttle valve within the
throttle body assembly. The injector fires twice per
engine revolution under most operating conditions.
On 1.8 liter engines, four injectors are used. The
fuel is distributed to the injectors via the fuel rail. All
injectors fire simultaneous ly once per engine revolu-
tion under most operating conditions.
Under conditions of high load the control unit
may signal the injector(s) to fire more often. However,
if the engine speed exceeds 6 700 rpm the control unit
will cease firing the injectors until the engine speed is
below 6 200 rpm.
Fuel is supplied under pressu re by an electric fuel
pump mounted in the fuel tank and the pressure is
regulated by a pressure regulator.
On 1.6 liter engines, the regulator consists of a
spring tensioned diaphragm which is mounted to the
side of the throttle body assembly. The fuel pressure is
regulated by the tension of the spring against the
diaphragm, opening and closing the fuel return port.
On 1.8 liter engines, the pressure regulator is
mounted adjacent to the fuel rail and consists of a
diaphragm with fuel pressu re acting on one side and
spring tension and manifold vacuum acting on the
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 89 of 238
Fuel and Engine Management 89
The procedure for fabricating an LED test lamp is
fully described in the El ectrical System section.
If a conventional test lamp with a filament type
bulb is to be used, ensure that the current draw of the
test lamp does not exceed 0.3 amp to avoid damage to
the electronic components.
To check the current draw connect an accurate
ammeter, such as the multimeter described previ-
ously, in series with the test lamp and a battery.
If the ammeter reads less than 0.3 amp the test
lamp is suitable.
Tachometer
(1) Disconnect the resistor from the tachometer
pick-up wiring connector which is located on the
ignition coil wiring harness, and connect the positive
lead of an accurate tachometer to the brown wire
terminal in the wiring connector. (2) Connect the negative lead to a good earthing
point.
View showing the location of the tachometer pickup
wiring connector with the resistor installed.
Timing Light
(1) Connect the timing light to the engine fol-
lowing the instrument manufacturers instructions.
NOTE: Do not connect or disconnect the
timing light with the engine running as
voltage surges could damage the alternator
or control unit. Do not allow the high
tension leads to open circuit with the engine
running as damage to the engine manage-
ment system could result.
(2) Do not connect the timing light positive lead
to the alternator output terminal. Where possible,
connect the power leads of the timing light to an
external power source to prevent possible transient
voltages damaging the alternator or control unit.
4. SYSTEM DIAGNOSIS AND ADJUSTMENTS
NOTE: Due to the use of complex electronic
components in the engine management sys-
tem, the diagnosis and testing procedures
described in this section should not be
carried out by persons lacking an under-
standing of electronics and the precautions
associated with the servicing of electronic
components. It is rec ommended that should
a fault arise in the system, the vehicle be
referred to an authorized workshop.
The control unit can be damaged by
component faults not indicated by the self
diagnosis codes and the renewal of the
control unit without lo cating the cause of
the failure will result in the failure of the
replacement unit. It is for this reason that
the practice of substituting components to
isolate faults is not recommended.
Prior to performing any of the follow-
ing operations, refer to the Service Pre-
cautions and Procedures heading.
PRELIMINARY CHECKS
Prior to performing the Self Diagnosis Test Pro-
cedures, perform the following preliminary checks and
rectify any problems as necessary.
(1) Check for an adequate supply of fuel in the
fuel tank. (2) Check the wiring connectors and earth points
of all engine management components for clean,
secure connections. To prevent damage to the control
unit, disconnect the negative battery terminal before
disconnecting any engine ma nagement wiring connec-
tors. (3) Check the condition of the battery. Refer to
the Electrical System sectio n for checking procedures.
Rectify any faults as necessary. (4) Check the air cleaner element for restriction.
(5) Check for air leaks at the throttle body, inlet
manifold and all related hoses. (6) Check the fuel pump pr essure as described
later in this section. (7) Ensure that the engine is in a satisfactory
mechanical condition and is in tune. Refer to the
Engine and Engine Tune-up sections as necessary.
SELF DIAGNOSIS
This function is very useful in locating system
faults particularly intermittent problems. However,
the self diagnosis mode does not provide comprehen-
sive testing of the engine management system, and
therefore should always be used in conjunction with
the other test procedures described later, in order to
accurately locate system faults.
To Interpret Self Diagnosis Codes
Once the self diagnosis mode is activated, various
fault codes will be displayed as a series of flashes by
the ECM warning lamp on the instrument cluster.
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 91 of 238
Fuel and Engine Management 91
components, erase the self diagnosis memory as
described under the following heading.
(7) Repeat the self diagnosis test procedure and
ensure that code 12 is displayed.
To Erase Memory
(1) With the ignition Off, remove the fusible link
that is positioned third from the front of the fusible
link connecting block located at the rear of the
battery. (2) Install the fusible link after 10 seconds.
View showing the location of the fusible links.
TO CHECK AND ADJUST IGNITION TIMING
(1) Connect a timing light to the engine as
previously described under the Service Precautions
and Procedures heading.
(2) Start the engine and allow it to reach normal
operating temperature. (3) Connect a jumper lead between terminals A
and B on the diagnostic link connector. (4) With the engine idling at the specified speed,
check the ignition timing with the timing light.
The timing mark on the crankshaft pulley should
be aligned with the pointer on the inner liming belt
cover.
(5) If necessary, loosen the distributor body
retaining nuts and turn the distributor until the timing
marks are aligned. (6) Tighten the distributor body retaining nuts
and check that the timing is correct. (7) Remove the jumper lead from the diagnostic
link connector and disconnect the timing light from
the engine.
TO ADJUST BASE IDLE SPEED
NOTE: The idle speed is controlled by the
idle air control (IAC) valve and is not
adjustable. The throttle stop screw controls
the base idle speed a nd is factory set. The
following base idle speed adjustment should
only be performed if the throttle body has
been renewed, or if comprehensive testing of
related components indicates that adjust-
ment is required.
(1) Before adjusting the base idle speed perform
the following tests;
(a) Check the spark plug gaps, the high tension
leads and the ignition timin g as described previously
in the Engine Tune-up section.
(b) Check the air inlet syst em for leaks between
the throttle body and inlet manifold and the inlet
manifold and cylinder head.
NOTE; Any vacuum leaks will make the
engine idle faster than it should.
(c) Check that all wiring connectors and vacuum
hoses are securely connected. (d) Ensure that the transaxle is in Park or
Neutral. (e) Ensure that the air cleaner element is service-
able.
(2) On 1.6 liter engines, remove the air cleaner
assembly, disconnect the vacuum hose from the
throttle body and seal the vacuum hose fitting.
(3) Ensure that the throttle valve moves freely
and returns to the fully closed position when slowly
released. (4) Connect an accurate tachometer to the en-
gine as previously descri bed under the Service Pre-
cautions and Procedures heading.
(5) Start the engine and allow the engine to
warm up and the idle rpm to stabilize. Check that all
electrical accessories and the air conditioning, if
equipped, are turned off. (6) With the engine idling in Park or Neutral,
slowly disconnect the brake servo unit vacuum supply
hose from the inlet manifold. Allow the engine to run
for one minute.
Location of the base idle adjusting screw. 1.8 liter
engine.