1987 NISSAN PULSAR check engine light

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.

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.

Fuel and Engine Management 95
(3) Disconnect the vacuum hose from the pres-
sure regulator.
(4) Release the fuel hose clamps, disconnect the
hoses from the pressure regulator and remove the
pressure regulator. Installation is a reversal of the removal procedure
ensuring that the fuel hose clamps are tightened
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 cleaner assembly. If neces-
sary, refer to the Air Cleane r Assembly heading in this
section. (4) Remove the screws securing the pressure
regulator cover to the throttle body assembly. When removing the final screw hold the cover
firmly as it is under spring tension.

(5) Remove the cover, spring seat, spring and
diaphragm from the thrott le body assembly. Discard
the diaphragm.


View of the pressure regulator components removed
from the throttle body assembly. 1.6 liter engine.
Installation is a reversal of the removal procedure
with attention to the following points:

(1) Install a new diaphragm ensuring that
the
diaphragm is correctly seat ed in the groove in the
throttle body assembly. (2) Apply Loctite 262 to the threads of the
retaining screws.
(3) Place the spring seat and the spring in the
cover and install the cover to the throttle body
assembly, ensuring that the cover is positioned on the
locating dowels. (4) While holding the cover in position install
the
retaining screws and tighten securely.
NOTE: When installing the pressure regu-
lator cover ensure that the diaphragm is not
disturbed, to prevent the possibility of a fuel
leak.

INJECTORS
To Test Injector Circuit and Injectors
(1) Disconnect the injector wiring connectors.
(2) Connect a test lamp between the injector
wiring connector terminals, ensuring that the test
lamp probes do not contact each other. (3) With the ignition switched On the test lamp
should not light. On 1.8 liter engines, check each of
the other connectors.
If the test lamp lights check the wiring harness for
a short to earth between the injector wiring connec-
tor(s) and the control unit wiring connector termi-
nal - D15 and D16 on 1.8 liter engines, or D16 on
1.6 liter engines.

(4) With the aid of an assistant, operate the
starter motor. The test lamp should flash. On 1.8 liter
engines, check each of the other connectors.

If the test lamp does not flash when connected to
the injector wiring connecto r(s), proceed to operation
(6).

If the test lamp lights as described, proceed as
follows.

If the test lamp lights but fails to flash, a faulty
control unit is indicated. Pr ior to renewing the control
unit, check the condition of the injectors as follows.

(5) Connect an ohmmeter between the terminals
of the injectors).

The resistance should be more than 1.2 ohms on
1.6 liter engines or more than 12 ohms on 1.8 liter
engines.

If the injector resistance is as specified, the
injector circuit can be considered serviceable.

If the injector resistance is not as specified, renew
the faulty injector(s).

(6) With the ignition switched On, probe the
injector wiring connector terminals with a test lamp to
earth.

If the test lamp lights when the probe contacts the
pink wire terminal on 1.6 liter engines, or the white
wire terminal on 1.8 liter engines, check the wiring
harness for a short to volt age between the injector
wiring connector(s) and the control unit wiring con-
nector terminal(s) D16 on 1.6 liter engines, or D15
and D16 on 1.8 liter engines.

If the test lamp does not light when the probe
contacts the blue wire termin al on 1.6 liter engines, or
the black and red wire term inal on 1.8 liter engines,
check the EGI relay and circ uit as described under the
EG! and Fuel Pump Relays heading in this section.

If the test lamp lights when the probe contacts the
blue wire terminal on 1.6 lite r engines, or the blue and
red wire terminal on 1.8 liter engines, proceed as
follows.

(7) Switch the ignition Off and connect the
injector wiring connectors). (8) Switch the ignition On and, using a test lamp
to earth, backprobe the cont rol unit wiring connector

96 Fuel and Engine Management

terminal D16 on 1.6 liter engines, or D15 and D16
on
1.8 liter engines.

The test lamp should light.
If the test lamp does not light check the wiring
harness for continuity between the injector wiring
connector(s) and the control unit wiring connector
terminals.

Repair or renew the wiring harness as necessary.
To Remove and Install Injectors and Fuel Rail — 1.8
Liter Engine.

(1) Depressurize the fuel system as previously
described.
(2) Disconnect the negative battery terminal.
(3) Thoroughly clean around the injectors and

View of the fuel rail, injectors and pressure regulator
removed from the engine.
the fuel rail to prevent foreign material entering the
engine.

(4) Suitably mark the fuel hoses, loosen the hose
clamps and disconnect the fuel hoses from the fuel
rail. (5) Disconnect the vacuum hose from the fuel
pressure regulator. (6) Loosen the hose clamp and disconnect the
engine ventilation hose from the throttle body. (7) Remove the bolts securing the fuel rail and
injectors to the inlet manifold. (8) Carefully raise the fuel rail and injectors
from the inlet manifold until the injector nozzles are
clear of the manifold. (9) Disconnect each injector wiring connector by
pushing in the wire retaining clip.
(10) Using a small screwdriver, remove the injec-
tor retaining clip and withdraw the injectors from the
fuel rail.
Installation is a reversal of the removal procedure
with attention to the following points:

(1) Check the condition of the injector O ring
seals and renew if necessary. (2) Install the injectors to the fuel rail and secure
with the retaining clips. (3) Connect the wiring connectors to each injec-
tor ensuring that the wire clip is locked in position. (4) Install the injectors to the inlet manifold,
carefully guiding the injectors into place ensuring that
the O ring seals are not damaged.
(5) Install the fuel rail retaining bolts and tighten
to the specified torque. (6) Install the fuel hoses to the fuel rail
and
tighten the hose clamps securely.
(7) Check for fuel leaks as previously described.
To Remove and Install Injector — 1.6 Liter Engine

(1) Depressurize the fuel system as previously
described. (2) Disconnect the negative battery terminal.
(3) Remove the air cleaner assembly. If neces-
sary refer to the heading Air Cleaner Assembly in this
section.
(4) Remove the injector retaining plate screw
and remove the injector retaining plate from the
throttle body assembly. (5) Insert the blade of a screwdriver from the
front of the throttle body assembly under the rim of
the injector in which the retaining plate locates.
Support the screwdriver on a suitable object to act as
a fulcrum. (6) Carefully lever the screwdriver until the
injector can be withdrawn from the throttle body
assembly.
(7) Remove and discard the upper and lower O
ring seals from the injector . If necessary remove the
lower filter screen from the injector.
NOTE: As the injector contains electrical

View of the fuel injector removed from the throttle body assembly. 1.6 liter engine.

Fuel and Engine Management
(8) Remove the bolts retaining the intermediate
exhaust pipe to the rear of the catalytic converter,
remove the bolt securing the exhaust mounting to the
underbody and slightly lower the intermediate exhaust
pipe. Support the intermediate pipe to prevent the
tailpipe fouling the lower bumper panel.
(9) Remove the bolts retaining the stabilizer bar
mounting brackets to the underbody and allow the
stabilizer bar to drop.
(10) Remove the bolts retaining the exhaust heat
shield to the underbody, located at the front of the
fuel tank. (11) Remove the handbrake cable mounting
bracket retaining nuts and remove the mounting
brackets from the mounting studs. (12) Remove the fuel tank retaining bolts and
maneuver the fuel tank from the vehicle. Installation is a reversal of the removal procedure
with attention to the following points:

(1) When installing the fuel tank, ensure that the
fuel pump wiring harness is directed through the
aperture in the floor. (2) Install the stabilizer bar mounting
bracket
bolts and tighten to the specified torque. Refer to the
Rear Suspension section.
(3) Using a new gasket, install the intermediate
exhaust pipe to the catalyti c converter ensuring that
the earth wire terminal is installed and tighten the
bolts securely. (4) Connect the fuel filler neck hose, the fuel
check valve hose and the breat her hose ensuring that
they are secured firmly. (5) Tighten the fuel tank drain plug to the
specified torque. (6) Connect the fuel hoses to the fuel pump,
using the marks made during removal to ensure
correct installation. (7) Install the fuel pump wiring harness and the
rubber grommet to the fuel pump cover plate. Install
the cover plate and tighten the retaining bolts se-
curely.
(8) Connect the fuel pump wiring connector
securely. (9) Check for fuel leaks as previously described.
6. AIR FLOW COMPONENTS
NOTE: Before proceeding with any of the
operations in this section, refer to the Ser-
vice Precautions and Procedures heading.

AIR CLEANER ASSEMBLY
To Renew Element
The procedure for renewing the air cleaner ele-
ment is covered in the Engine Tune-up section.

To Remove and Install — 1.8 Liter Engine
(1) Disconnect the negative battery terminal.
(2) Release the air intake hose retaining clamps,
disconnect the hose from the air cleaner upper
housing and the throttle body and remove the hose. (3) Remove the screw securing the air cleaner
intake duct to the front panel mounting bracket. (4) Remove the hexagon head screws retaining
the air cleaner mounting bracket to the right hand
inner mudguard and remove the air cleaner from the
engine compartment. (5) Release the upper housing retaining clips,
separate the upper housing from the lower housing
and remove the element. (6) Remove the air cleaner intake duct retaining
screw and disconnect the duct from the lower air
cleaner housing. (7) If necessary, remove the bolts securing the
mounting bracket to the ai r cleaner lower housing and
separate the mounting bracket from the housing. (8) Thoroughly clean the upper and lower hous-
ings in cleaning solvent and check for cracks, splits 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) Ensure that the r ubber insulators are in-
Dismantled view of the ai r cleaner assembly. 1.8 liter
engine.

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.

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.

\(V2 Fuel and Engine Management


View of the IAC valve removed from the engine. Dimension A must not exceed 28 mm.
(3) Lubricate the IAC valve O ring with engine
oil and install the IAC valve. Tighten the retaining
screws securely.

(4). Install the IAC valve wiring connector and
the negative battery terminal.

(5) On 1.6 liter engines, install the air cleaner
assembly as previously described. (6) Run the engine until normal operating tem-
perature and idle speed are attained.
NOTE: Several minutes may elapse before
the normal idle speed is attained.

(7) Hold the throttle open at approximately
3 000 rpm for 10 seconds to reset the IAC valve.

MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR

To Test - Codes 33 and 34
NOTE: The following test procedure
assumes that fault codes 33 or 34 have
been
displayed during the self diagnosis test
pro-
cedure. If no codes have been displayed
but
the operation of the MAP sensor is suspect,
begin the test procedure at operation (15).
(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.
(3) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. Note any fault codes
displayed. If code 34 is displayed, remove the jumper lead
from the diagnostic link connector, erase the self
diagnosis codes and proceed to operation (7).

If code 33 is displayed, remove the jumper lead
from the diagnostic link connector, erase the self
diagnosis code memory and proceed to operation (4).

If no codes are displayed, but codes 33 or 34
were
displayed when the self diagnosis test procedure was
originally performed, an intermittent fault is indi-
cated. Proceed as follows:

(a) Check for faulty wiring connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(c) Check the vacuum hose to the MAP sensor
for deterioration or restriction.
(4) Disconnect the wiring connector from the
MAP sensor. (5) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. (6) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. Note any fault codes
displayed.
If code 33 is displayed, measure the voltage at
the
MAP sensor wiring connector terminal B with a
voltmeter to earth. Renew the control unit if the
voltage is less than 1 volt.

If the voltage is more than 1 volt, check the
wiring
harness for a short to voltage between terminal B and
the control unit wiring connector terminal Cll.
Repair or renew the wiring harness as necessary.

If code 34 is displayed, proceed as follows:
(a) Check for a restricted or leaking MAP sensor
vacuum hose.
(b) Check the wiring harness for continuity and
shorts between terminals A on the MAP sensor
connector and terminal A11 on the control unit wiring
connector. Repair or renew the wiring harness as
necessary.
If no faults are indicated in the above two checks,
proceed to operation (15).

(7) Disconnect the wiring connector from the
MAP sensor and connect a jumper lead between
terminals B and C on the wiring connector. (8) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. (9) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector. Note any fault codes
displayed.
If code 33 is displayed, proceed to operation (15).
If code 34 is displayed, proceed as follows.

Location of the MAP sensor. Inset shows the terminal
identification.