1977 DATSUN PICK-UP oil

Engine
Tune

up

EC284

When

installing
this
valve

ensure

that
it

properly
oriented
This
valve

should
be

replaced
periodically
Refer

to
Maintenance
Schedule

I

To

distribut0
From

carburetor

Yl
r

EC278
l

Fig
ET
24
Operation
of
spark
delay

value

I

I

Carburetor
side

Distributor
side

rJmlL
lr

EC346

Fig
ET
25
Checking

spark
delay
value
Distributor
side

Brown

lOne
way
umbrella
valve

2
Sintered
metal
disc

Fig
ET
23
Spark
delay
valve

INSPECTION

I
Remove

spark
delay
valve

2
Blow
air

through
port
on

carbure

tor
side
then

through
the

other
port

on
distributor
side

Spark
delay
valve

is
in

good
condition
if
when

finger
is

placed
over

port
on
distrib
side

ajr
flow
resistance
is

greater
than
that

on
the
other

side
See

Figure
ET
25

3
If
a
considerable
air
flow
resist

ance
is
felt
at

port
on
distributor
side

in

step
2

above
and

if
the
condition
of

spark
delay
valve
is

questionable
dip

port
on
carburetor

side
into
a

cup

fIlled
with
water
Blow
air

through
the

other

port
Small
air
bubbles
should

appear

EC279

Fig
ET
26

Checking
spark
delay
ualue

Note
Be

careful
to

avoid

entry
of
oil

or
dirt
into
valve

ET
15
CHECKING

AUTOMATIC

TEMPERATURE

CONTROL
AIR

CLEANER

1
Air
cleener
element

Viscous

paper
type
air
cleaner
ele

ment
does
not

require
any
cleaning

opera
tion

until
it
is

replaced
periodi

cally
Brushing
or

blasting
operation

will

cause

clogging
and
result
in
enrich

ment
of
carburetor
mixture
and

should
never
be
conducted
For
reo

placement
interval
of
air
cleaner
ele

ment
refer

to
Maintenance
Schedule

2
Hot

elr
control
system

In
warm
wealher
it
is
difficult
to

find
ou

t
malfunction
of
hot
air
control

system
In
cold
weather
however

malfunction
of
air
control
valve
d

e
to

disconnection
or
deterioration
of
vacu

um
hose
between
intake
manifold
and

vacuum
motor
and
insufficient
dura

bili

ty
of
air

con
trol
valve
will
cause

insufficient
automatic
control

opera

tion
for
intake
air
and
result
in

engine

disorder

including

I

Stall
or
hesitation
of

engine

opera

tion

2

Increase
in
fuel

consumption

3
Lack
of

power

These

phenomena
reveal
malfunc

tionof
hot
air
control

system
If
these

phenomena
should
occur
check
hot

air
control

system
as
described
in
the

following
before

carrying
ou

t

inspec

tion
of
carburetor

2
1
Vacuum
hoses

Intake
manifold
to
3

way
connec

tor
3

way
connector
to

temperature

sensor
3

way
connector
to
idle
com

pensator
temperature
sensor
to

vacu

um
motor

1

Check
that
vacuum
hoses
are
se

curely
connected
in

correct

position

2
Check
each
hose
for
cracks
or

distortion
hose

clip
for
condition

r

CHECKING
B
C

D
D

SOLENOID
VALVE

I
Turn
on

engine
key
Do
not
start

engine

2
Ensure
that
solenoid
valve

clicks

when

intermittently
electrified
as

shown
in

Figure
ET
37

Fig
ET

37

Checking
solenoid
uolV
l

I

l

EF264

2

Turn

ignition
key
to
ON

posi

tion

3

Ensure
that
tester

pointer
deflects

when

ignition
key
is

turned
on

4

If

tester

panter
does
not
deflect

when

solenoid
valve

and

speed
detect

ing
switch

circuits

are

functioning

properly
amplifier
is

faulty
Engine
Tune

up

3
If
a

click
is

heard
solenoid
valve

is
normal

4

If
a
click
is
not
heard

at
all
check

for

continuity
with
a
circuit

tester
If

discontinuity
is

detected

replace
sole

naid
valve

CHECKING

AMPLIFIER

Manual
transmission

models

The

amplifier
is

installed
at
the

rear

of
the

speedometer
To

check

proceed

as
follows

1
Set
circuit

tester
in

d
c

ampere

range
IA

min
full
scale

connect
test

probes
of
tester
as

shown
in

Figure

ET
38

Do

not
confuse

positive
line

with

negative
line

M

p
1

II

L
o

A

I
of

j
t
J

f

T

1

Ignition
key

2

Amplifier

3

Speed

detecting
switch

4
B

C
D

D

solenoid
valve

Fig
ET
38

Checking

amplifiu

REPLACING
AIR

PUMP
AIR
CLEANER

ELEMENT

Remove
air

hose
then
detach
air

cleaner
from

hoodledge
Air
cleaner

element

and
air

cleaner
lower

body
are

built
into

a
unit
construction

Replace

air

cleaner
element
and
lower

body
as

an

assembly

ET

20
EC323

Fig
ET
39

Repl4cing
air
cleaner

element

CHECKING

EXHAUST

GAS

RECIRCULATION

E
G

R

CONTROL

SYSTEM

Checkln

E
G
R
control

system
In
Ita

mounted

condition

I

M
ake
a

thorough
visual
check
of

E

G
R
control

system
If

necessary

wipe
away
oil
to

facilitate

inspection

If

hoses
are

cracked
or

broken
fe

place

2
With

engine
running
check

E
G
R

warning
system
for

proper

function
Make
sure
that
E

G
R
warn

ing
lamp
light
when

ignition
switch
is

turned
to
START

position
starter
mo

tor
runs
If
E
G
R

warning
lamp
does

not

light
inspect
harnesses
and
con

nectors
or

replace
warning
lamp
Then

turn

ignition
switch
to

ON

position

and
check
the

following
items

I

If
odometer
of
detector
drive

counter
has
not
reached
50

000

counts
make
sure
that
E

G
R

warning

lamp
does
not

light

2

If
odometer
of
detector
drive

counter
has
attained
50

000
counts

make

sure
that
E

G
R

warning

lamp

lights

If

warning

lamp
does
not

light

check
harnesses

connector
and
de

tector
drive
counter

replace

warning

lamp
or
detector
drive

counter
if

necessary

Note

Operation
of
E

G
R

warning

lamp
is

as
follows

Replace
bulb
if

bulb
is
burned

ou
t

If

bulb
is
not
burned
trace

wireis

back

to

ignition
switch

Repair
or

replace
if

necessary

2

Be
sure
that

floor

temperature
is

cool

below
800C

1760F
before

carrying
out
the

following
procedure

1
Remove
rear
seat

2

Ignition
switch
is
turned
to

the

Temperature

sensing
switch
Temperature

warning
lamp

Contact
close
Off

Contact

open
On

Note

Avoid

heating
floor

tempera

ture

sensing
switch
directly

If

lamp
does

not

glow
check
floor

temperature
sensing
switch
connector

for

continuity
with
a
circuit

tester

If

continuity
should
exist

after

heated

surrounding
areas
of
floor
tern

rv
wnTP
sen
cinq
S
Vitch

reolace
tem

perature
sensing
switch

If

continuity
does
not
exist

trace

the

wiring
back
to

relay
or
check
the

following
step
3

Repair
or

replace

wire

s
if

necessary

Note
The
floor

temperature
sensing

switch

may
be
heated

through
the

floor

by
a

proper
heater

3
Turn

ignition
switch
to
the
IG

position
anf
disconnect
floor

temper

ature

sensing
connector
The

lamp

should
remain

on
If
not

check
floor

4
0
3

UJ

GJO
Engine
Tune

up

IGU

position

3
Ensure

that
floor
tem

perature

warning

lamp
goes
out

4

Heat

surrounding
areas
of
floor

temperature
sensing
switch
with
a

proper
heater

to
ensure
that
floor

temperature
warning

lamp
glows
when

floor
is

heated
to

lh

specifications
as

shown

in
the
table
below

Floor

temperature

Below

1050C

22IOF

Above
1050C

2210F

temperature
relay
for

continuity
with

a

circuit
tester

Referring
to
the

following
floor

temperature
relay
if

relay
is
normal

trace

wire
s
back
to

ignition
switch

Repair

faulty
wiring

Floor

temperature

rela

To

check
floor

temperature
relay

remove
it

and

proceed
as

follows

1
Check
for

continuity

between@

and

@
Continuity
should

exist

Check
for

continuity
between

D

and@
Continuity
should
exist

Check
for

continuity
between

D

and@
Continuity
should
not
exist

2

Apply
a
12
volt
doC

across@and

@
to

ensure
that

continuity
exists

between

D
and@and
that

continuity

does
not
between

D
and

@
If
test

r
I

141

ET
24
results
do
not

satisfy
the
above
reo

place
the
floor

temperature
relay

When
floor

temperature

warnln8
lamp
118hts

Check
floor

temperature
warning

lamp

I

Open
or

short
circuit
in

wiring

harness

2

Check
fuel

system
with

regard
to

the

following
items
Refer
to

Inspec

tion

of
Fuel

System

I
Floa

t
level

2

Choke

3

Normal

fuel

supply
system
Prima

ry
and

secondary

4

Accelerator

pump

5

Power
valve

6

B
C
D
D

7

Fuel
strainer

8
Air

cleaner

3
Check

ignition
system
with

regard

to

the

following
items
Refer

to

Inspection
of

Ignition
System

I

IgnItion
AMI

2

Distributor

3

Ignition
coil

4

High
tension

code

5

Spark

plug

4

Check

idle
CO

adjustment
Refer

to

Inspection
of
Idle

CO

Adjust

roeoC

Note
Even

if
there
is

nothing
wrong

with

engine

warning
lamp
may

come
on
if
vehicle
is

being
driven

on
a

steep
slope
continuously
in

lower

gears
at

high
engine

speeds

To
floor

temperature

warning
lamp

2
From
S

position

3
From
GOt

position

4

From

ignition
switch

5
To
floor

temperature

sensing
switch

EC343

Fig
ET
50

Checking
floor

temperature

relay

Engine
Tune

up

TROUBLE
DIAGNOSES
AND

CORRECTIONS

Condition
Probable
cause

CANNOT
CRANK

ENGINE
OR

SLOW

CRANKING
Improper
grade
oil

Discharged
battery

Faulty
battery

Loose

fan
belt

Malfunction
in

charge
system

Wiring
connection
loose
in

starting
circuit

Faulty
ignition
switch

Faulty
starler
motor

Trouble

shooting
procedure
on

starting
circuit

Switch
on
the

starting
motor
with

light
ON

When

light
goes
off
or
dims

considerably

a
Check

battery

b
Check
connection
and

cable

c
Check
starter
motor

When

light
stays
bright
Corrective
action

Replace
with

proper
grade
oiL

Charge

battery

Replace

Adjust

Inspect

Correct

Repair
or

replace

Repair
or

replace

a
Check

wiring
connection
between

battery
and
starter

motor

b
Check

ignition
switch

c
Check
starter
motor

ENGINE
WILL
CRANK

NORMALLY
BUT

WILL
NOT

START

In
this
case
the

following
trouble
causes

may
exist

but
in

many
cases

ignition

system
or
fuel

system
is
in

trouble

Ignition

system
in
trouble

Fuel

system
in
troubk

Valve
mechanism
does
not
work

properly

Low

compussion

Trouble

shooting
procedure

Check

spark
plug
firstly
by

following
procedure

Disconnect

high
tension
cable
from
one

spark
plug
and
hold
it

about
10
mm
0
39
in

from
the

engine
metal

part
and
crank

the

engine

Good

spark
occurs

Check

spark
plug

b
Check

ignition
timing

c
Check
fuel

system

d
Check

cylinder
compression

Check
the
current
f10
in

primary
circuit

Very
high
current

Inspect
primary
circuit
for
short

Check
breaker

poiIit
operation

except
tran

sistor

ignition
system
No

spark
occurs

ET

27

Engine
Tune

up

Condition

Probable

cause

Low
or
no

current

Ign
tion

system
out
of

order
Burned
distributor

point

Improper
point

gap

Faulty
condenser

Leak
at
rotor

cap
and

rotor

Faulty

spark

plug

Improper
ignition
timing

Faulty
ignition
coil

Disconnection

of

high
tension

cable

Loose
connection
or
disconnection
in

primary
circuit

Fuel

system
out
of

order
Lack
offuel

Dirty
fuel
strainer

Dirty
or

clogged
fuel

pipe

Fuel

pump
will
not
work

properly

Carburetor

choke
will
not
work

properly

Improper

adjustment
of
float
level

Improper
idling

Dirty
or

clogged
carburetor

Clogged
breather

pip
of
fuel
tank

Malfunctioning
an
ti

dieseling
solenoid
valve

Incorrect
sparle

plug
tightening
or

faulty

gasket

Improper
grade
engine
oil
or
low

viscosity

Incorrect
valve
clearance

Compression
leak
from
valve

seat

Sticky
valve

stem

Weak
or

damaged
valve

springs

Compression
leak
at

cylinder
head

gasket

Sticking
or

damaged
piston
ring

Worn

piston

ring
or

cylinder

Trouble
ooting

procedure

Pour

the

engine
oil
from

plug
hole
and
then

measure

cylinder

compression

Compression
increases

Compression
does

not

change
Low

comp
ion

ET
28
Corrective
action

Check
for
loose

terminal
or
disconnection

in

primary
circuit

Check
for

burned

points

Repair
or

replace

Adjust

Replace

Clean

or

replace

aean

adjust
plug
gap
or

replace

Adjust

Replace

Replace

Repair
or

replace

Supply

Replace

Clean

Repair
or

replace

Check
and

adjust

Correct

Adjust

Disassemble

and
clean

Repair
and
clean

Check
for

loose
terminal
or
wire
harness

Tighten
to
normal

torque
or

replace
gasket

Replace
with

proper
grade
oil

Adjust

Remove

cyljnder
head

and

lap
valves

Correct
or

replace
valve

and
valve

guide

Replace
valve

springs

Replace

gasket

Replace
piston
rings

Overhaul

engine

Malfunctiong

cylinder
or
piston
ring

Compression
leaks
from
valve

cylinder
head

or
head

gasket

Except
transistor

ignition
system

Condition

IMPROPER
ENGINE

IDLING

Fuel

system
out
of

order

Low

compression

Others

High
engine
idle

speed
Engine
Tune

up

Probable
cause

Clogged
or

damaged
carburetor

jets

Incorrect
idle

adjustment

Clogged
air
cleaner
filter

Damaged
manifold

gaskets
or
carburetor

insulator

Improper
float
level

adjustment

Loose
air

hoses
or
air

fuel
mixture
hoses
of

carburetor

Malfunctioning
carburetor
choke

Malfunctioning
anti

backfire
valve

Malfunctioning
automatic

temperature
con

trol
air

cleaner

Inoperative
idle

compensator

Carbon
canister

purge
line
hose

damaged
or

disconnected

Stick
E

F
E
valve
shaft

Incorrect
valve
clearance

Extremely
low
revolution

Faulty
malfunction
of
the

ignition
system

spark
plug

high
tension
cable
breaker

point
ignition
coil
etc

Incorrect
basic

ignition
timing

Malfunction
of
choke
valve
or

linkage

Malfunction
of
vacuum
motor
sensor
or

hoses
of
air
cleaner

Incorrect
idle

adjustment

Clogged
air
cleaner
fdter

Malfunction
of
idle

compensator
of

air

cleaner

Malfunction
of
E
G
R
control
valve

Loose
manifold
and

cylinder
head
bolts

Dragged
accelerator

linkage

Incorrect
idle

adjustment

Malfunction
of
B
CDD

system

Malfunction
of

speed
switch
and
harness

ET
29
Corrective
action

Clean
or

replace

Adjust

Replace
element

Replace
gasket
or
insulator

Adjust

Check
for
loose
connections

Check
and

adjust

Check
for
loose
connection
of
vacuum
hose

Check
A

r
C
air
cleaner

Check
for
connection
of
idle

compensator

hose

or
replace
idle

compen
tor

Connect
or

replace

Repair

Previously
mentioned

Adjust

Adjust

Replace

Adjust

Adjust

Check
for
loose
hoses

Replace
system
com

ponents
if
necessary

Adjust
idle

speed

Replace
air
cleaner
fdter

Replace

Clean
or

replace

Retighten
bolts

Check
and

correct
accelerator

linkage

Adjust
idle

speed

Check
for
loose

vacuum
hose
and
harness

connections

Adjust
or

replace
if

necessary

Check
for
loose
connections

Repair
or

replace
if

necessary

Condition

ENGINE
POWER
NOT

UP
TO
NORMAL

Low
compression

Ignition
system
out
of

order

Fuel

system
out

of

order

Air
intake

system
out

of
order

Emission
control

Overheating

O

cooIing

Others
Engine
Tune

up

Probable
cause

Incorrect

iSnition
timing

Damaged

spark
plugs

Worn
distributor

points

Malfunction
of
choke

system

Clogged
fuel

pipe
or

floating
valve

Dirty
or

clogged
fuel
strainer

Fuel

pump
will
not
work

properly

C10ssed
carburetor

jets

Malfunction
of
altitude

compensator

CIOJBed
air
cleaner

Ail

inhaling
from
manifold

gasket
or

carburetor

gasket

Malfunction
of

E
G
R
valve

Stick
E
F
E

valve
shaft

Insufficient
coolant

Loose
fan
belt

Worn
or
oiled
fan
belt

Inoperative
thermostat

Worn
water

pump

Clogged
or

leaky
radiator

Worn
radiator
filler

cap

Ail

in

cooling
system

Improper
engine
oil

grade

Incorrect

ignition
timing

Clossed
carburetor
lean
mixture

Disconnected
altitude

compensator
hOlle

Inoperative
thermostat

Improper
octane
fuel

L

j
tire

pressure

Dragging
brake

Clutch

slipping

ET

30
Corrective
action

Previously
mentioned

Adjust

Clean

adjust
or

replace
plull

Dress

or

replace
points
Also
check

condenser

Adj
lst

Clean

Replace

Repair
or

replace

Disassemble
and
clean

Check
and

replace

Replace
element

Replace
gasket

Check
and
replace

Repair

Replenish

Adjust
fan
belt

Replace

Replace

Replace

Flush

repair
or

replace

Replace

Retighten
each

part
of

cooling
system

Replace
with

proper
grade
oil

Adjust

Overhaul
carburetor

Connect

Replace

Replace
with

specified
octane
fuel

Inflate

to

specified

pressure

Adjust

Adjust

Except
transistor

ignition
system

Condition

NOISY

ENGINE

Car

knocking

Mechanical

knocking

Crankshaft

bearing

Imocking

Connecting
rod

bearing
knocking

Piston
and

cylinder

noise

Piston

pin
noise

Water

pump
noise

Air

pump
noise

Others
Engine
Tune

up

Probable
cause

Overloaded

engine

Carbon

knocking

Timing
knocking

Fuel

knocking

Preignition
misusing
of

spark
plug

This

strong
dull
noise
increases
when

engine

is

accelerated
To
locate
the

place
cause
a

misfire

on
each

cylinder
If
the
noise

stops

by
the
misfire
this

cylinder
generates
the

noise

This
is
a
little

higher
pitched
noise
than
the

crankshaft

Imocking
and
also
increases

when

engine
is
accelerated
Cause
a
misfire

on
each

cylinder
and
if
the
noise
deminishes

almost

completely
this
crankshaft

bearing

generates
the
noise

When

you
hear
an

overlapping
metalic
noise

which
increases
its

magnitude
with
the

revolution
of

engine
and
which
decreases
as

engine
is
warmed

up
this
noise
is
caused

by

piston
and
cylinder
To
locate
the

place

cause
a
misfire
on
each

cylinder

This
noise
is

heared
at
each

highest
and

lowest
dead
end
of

piston
To
locate

the

place
cause
a

misfire
on
each

cylinder

This
noise

may
be
caused

by
worn
or

damaged
earings
or
by
the
uneven
surface

of
sliding

parts

Damaged
air

pump

An
improper
adjustment
of
valve
clearance

Noise
of

timing
chain

An
excessive
end

play
on
crankshaft

Noisy
E
F
E

valve
shaft

Wear
on
clutch

pilot
bushing

Note
This
noise
will
be
heared
when

clutch
is

disengaged

ET31
Corrective
action

Use

right
gear
in
driving

Disassemble

cylinder
head
and

remove

carbon

Adjust
ignition
timing

Use

specified
octane
fuel

Use

specified
spark
plug

This
is

caused

by
worn
or

damaged
bearings

or
unevenly
worn
crankshaft
Renew

bearings
and

adjust
or

change
crankshaft

Check
lubrication

system

Same
as
the
case
of
crankshaft

bearings

This

may
cause
an
abnormal

wearing
of

cylinder
and
lower

compression
which
in

turn
will
cause
a
lower
out

put
power
and

excessive

consumption
of
oil

Overhaul

engine

This

may
cause
a
wear
on

piston
pin
or

piston
pin
hole

Renew

piston
and

piston

pin
assembly

Replace
water

pump
with
a
new
one

Repair
or

replace

Adjust

Adjust
the
tension
of
chain

Disassemble

engine
and
renew
main
bearing

Repair

Renew
bush

and

adjust
drive
shaft