1987 NISSAN PULSAR engine coolant

110 Fuel and Engine Management
originally performed, an intermittent fault is indi-
cated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Disconnect the wiring connector from the
coolant temperature sensor. (5) With the ignition switched On, measure the
voltage across the terminals on the coolant tempera-
ture sensor wiring connector. The voltage should be
4-6 volts.
If the voltage is below 4 volts, proceed to opera-
tion (9).

If the voltage is as specified, proceed as follows.
(6) Remove the coolant temperature sensor
from the vehicle. (7) Connect an ohmmeter to the coolant temper-
ature sensor terminals. (8) Immerse the meta1 end of the coolant
tem-
perature sensor in a 50/50 mixture of glycol and iced
water at a temperature of 0 deg C. The resistance
should be 6 000 ohms. Slowly heat the mixture and measure the resis-
tance of the coolant temperature sensor at the follow-
ing temperatures. Compare the results with the spec-
ified values:

0 d e g C ................................................. 6 000 ohms
20 deg C .................................................. 2 500 ohms
30 deg C .................................................. 1 800 ohms
40 deg C.................................................. 1 200 ohms
70 deg C .......................................................450 ohms
90 degC .......................................................250 ohms
100 deg C.....................................................190 ohms
110 deg C.....................................................110 ohms
If the resistances obtained are not as specified at
any of the given temperatures, renew the coolant
temperature sensor and retest for fault codes.

(9) Disconnect the control unit wiring connec-
tors.
(10) Check the wiring harness for shorts and
continuity between the coolant temperature sensor
wiring connector terminals and the control unit wiring
connector terminals C10 and D2. Repair or renew the
wiring harness as necessary.
Also check the control unit terminals for damage.
If no fault is found, renew the control unit and
retest for fault codes.

To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Disconnect the wiring connector from the
coolant temperature sensor.
(3) Drain the coolant as described in the Cooling
and Heating Systems section to a level below the
sensor.
(4) Unscrew the sensor from the thermostat
housing. Installation is a reversal of the removal procedure
with attention to the following points;

(1) Apply Loctite 675 or a similar conductive
sealer to the threads of th e sensor. Tighten the sensor
to the specified torque.
(2) Fill the cooling system with the correct
mixture of water and inhibitor as described in the
Cooling and Heating Systems section. (3) Ensure that the wiring connector is clean and
secure.
THROTTLE POSITION SENSOR
To Test - Codes 21 and 22

NOTE: The following test procedure as-
sumes that fault codes 21 or 22 have been
displayed during the se lf diagnosis test pro-
cedure. If no codes have been displayed but
the operation of the throttle position sensor
is suspect, begin the test procedure at oper-
ation (24).

(1) Erase the self diagnosis code memory as
previously described.
(2) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. If the engine will not start, disconnect the throttle
position sensor wiring co nnector and proceed to
operation (8). .

(3) With the engine id ling, quickly increase the
engine speed to 3 000 rpm and return to idle.

If the ECM warning lamp remains illuminated,
proceed to operation (4).

If the ECM warning lamp extinguishes, an inter-
mittent fault is indicated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connect or. Note any fault codes
displayed.

If codes 21 or 22 are displayed, proceed as
follows.

(5) Remove the jumper lead from the diagnostic
link connector. (6) Erase the self diagnosis codes as previously
described. (7) Disconnect the wiring connector from the
throttle position sensor. If code 22 was displayed in operation (4), proceed
to operation (13).

If code 21 was displayed in operation (4), proceed
as follows.

(8) Start and run the engine at idle speed for 2
minutes or until the ECM warning lamp lights. If the
engine will not start, pr oceed to operation (11).
(9) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on

114 Fuel and Engine Management
(6) Check the vehicle for the following:
(a) Low fuel pressure.
(b) Contaminated fuel.
(c) Vacuum leaks at the inlet manifold, engine
vacuum hoses and engine ventilation hoses. (d) Exhaust manifold leaks before the oxygen
sensor. (e) Correct MAP sensor operation.
(f) Blocked oxygen sensor metal vent cover eg.
plugged with mud etc. (g) Fuel injectors) partially blocked. Refer to a
fuel injection specialis t or a Nissan dealer.
If the above items have been checked and no
faults have been found, a faulty oxygen sensor is
indicated. Renew the oxygen sensor, run the engine
and ensure that no fault codes are set.

To Test — Code 45
(1) Run the engine until normal operating tem-
perature is attained. (2) With the ignition switched Off, connect a
jumper lead between terminals B and A on the
diagnostic link connector. (3) Start and run the engine at approximately
1 600-1 800 rpm for 2 minutes and note the ECM
warning lamp. If the ECM warning lamp is on more than off or
flashes at the rate of twice per second, proceed to the
following operation.

If the ECM warning lamp flashes evenly at the
rate of once per second an intermittent fault is
indicated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Switch the engine Off and disconnect the
oxygen sensor wiring connector. (5) Using a jumper lead, connect the oxygen
sensor wiring connector to a suitable engine earth. (6) Start and run the engine at 1 600-1 800 rpm
and note the ECM warning lamp.
If the ECM warning lamp extinguishes for at least
30 seconds, proceed to operation (7).

If the ECM warning lamp flashes on more than off
or flashes at the rate of twice per second, switch the
engine Off and disconnect the control unit wiring
connectors. Using an ohmmeter, check that there is no
resistance between the co ntrol unit wiring connector
terminal D6 and earth. Repair or renew the wiring as
necessary.

If no fault can be found in the wiring harness,
renew the control unit.

NOTE: The wiring harness for terminal D6
earths through the righ t hand rear cylinder
head bolt.

(7) Check the vehicl e for the following:
(a) High fuel pressure.
(b) Leaking injector(s).
(c) Faulty ignition wiring.
(d) Charcoal canister purge system blocked or
restricted.
(e) Faulty coolant temper ature sensor circuit.
(f) Faulty MAT sensor circuit (1.8 liter engine).
(g) MAP sensor operation.
(h) Throttle position sensor operation.

If the above items have been checked and no
faults have been found, a faulty oxygen sensor is
indicated.

Renew the oxygen sensor, run the engine and
ensure that no fault codes are set.

To Remove and Install
(1) If the engine is cold, run the engine for
approximately two minutes to allow easy oxygen
sensor removal. (2) Disconnect the negative battery terminal and
the oxygen sensor connector.

View of the oxygen sensor removed from the exhaust
manifold.
(3) Remove the exhaust manifold heat shield
retaining bolts and remove the heat shield from the
engine.
(4) Remove the oxygen sensor with a short ring
spanner using care not to damage the sensor wire. Installation is a reversal of the removal procedure
with attention to the following points:

(1) When installing a sensor that has previously
been removed, coat the sen sor threads with anti-seize
compound. Nissan recommend a mixture of liquid
graphite and glass beads. (2) Install the sensor and tighten to the specified
torque. (3) Connect the electrical connector ensuring
that the wiring is secured away from the exhaust. (4) Install the heat shield and tighten the retain-
ing bolts securely. On 1.6 liter engines, ensure that the hot air inlet
tube is located correctly be tween the heat shield and
the air cleaner housing.

(5) Start the engine and check for leaks.
VEHICLE SPEED SENSOR
To Test - Code 24

(1) Check the fuel pump and meter fuses. If the
fuses are serviceable, proceed to operation (5). If a
fuse is blown, rectify the cause and renew the fuse.

Electrical System 197
Switch on all lamps and allow them to
illuminate for approximately five minutes to reduce
the charge of the battery and to apply a load to the
circuit.
Start the engine and gradually increase the
speed to approximately 2 500 rpm. The reading on
the ammeter should be approximately 75% of the
rated output of the altern ator. See Specifications.
Switch off all the lamps and run the engine at
1 500-2 000 rpm until the indicated charge is below
10 amps. The voltmeter should now read in excess of
13.6 volts.
NOTE: Should the alternator fail to reach
the specific output, the unit will have to be
removed and overhauled or a replacement
unit installed.

Should the voltage reading be above or
below Specifications, the regulator will have
to be renewed.

TO REMOVE AND INSTAL
Disconnect the negative battery terminal.
On 1.8 liter engines, remove the bolt secur-
ing the air cleaner intake duct and remove the air
cleaner intake duct. Drain the radiator by releasing the radiator
drain plug, located at the bottom of the radiator and
allow the coolant level to fall below the thermostat
housing level. NOTE: Refer to the Cooling and Heating
Systems section when refilling the radiator
coolant to its correct l
evel, failure to do so
could result in severe damage to engine
components.

Remove the retaining bolts securing the
thermostat housing, disconnect the hose from the
radiator and remove the thermostat housing and
radiator hose from the vehicle. Using a socket and extension bar, remove the
bolt securing the alternator to the drive belt tensioning
bar located under the alternator. On vehicles not equipped with air condition-
ing, remove the front splash guard from under the
front of the vehicle and remove the bolt securing the
alternator to the drive belt tensioning bar. Loosen the upper mounting bolts, slacken
the alternator drive belt and remove it from the
alternator pulley.
While supporting the alternator, remove the
upper mounting bolts and remove the alternator from
the vehicle. Installation is a reversal of the removal procedure
with attention to the following points:

Do not over tension the drive belt. Refer
to
the Engine Tune-up section for the correct belt
adjusting procedure. Ensure that the wiring and connectors are
securely located on the alternator.

Dismantled view of the Bosch alternator.