NISSAN PULSAR 1987 Manual Online

Cooling and Heating Systems 81
continuous stream of bubbles indicates that the refriger-
ant charge is low.

A large number of bubbles or foam indicates that
the refrigerant charge is very low.

No bubbles or the presen ce of oil streaks in the
sight glass indicate that the system is completely
empty.

NOTE: If the outside air temperature is
high, a certain number of bubbles may be
observed in the sight gl ass, even though the
system is fully charged.

If the system requires recharging, the vehicle
should be taken to an authorized dealer for evacu-
ation, leak testing and recharging.

Do not operate the system if it is known that the
refrigerant charge is low as damage may result.

MAINTENANCE
The air conditioning system requires l i t t l e main-
tenance other than the following. Where applicable,
refer to the Lubrication an d Maintenance section for
the recommended service intervals.

(1) Check the refrigerant charge level in the
receiver/dryer sight glass. Recharge the system as
necessary. It is considered normal for the system to
require periodic recharging. (2) Inspect the air conditioner pipes and hoses
for leaks, deterioration and alignment. Evidence of oil
leakage is an indication of refrigerant leakage. Repair
or renew as necessary.
(3) Inspect the evaporator drain tube and the
condenser cooling fins for blockage. Clean as neces-
sary.
(4) Check the drive belt for deterioration and for
correct tension. Refer to the Engine Tune-up section
for the correct procedure.
(5) Operate the system at least once a week for
approximately 15 minutes to keep the compressor
seals lubricated.

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.

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.

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.

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

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.

Fuel and Engine Management 87

Fuel system wiring diagram for the 1.6 liter engine.

88 Fuel and Engine Management


Fuel system wiring diagram for the 1.8 liter engine.
BR K

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.

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.