1977 DATSUN PICK-UP heating

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

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

rr

ROCKER
ARM
AND

VALVE
ROCKER
PIVOT

Check

pivot
head
and
cam
contact

and

pivot
contact
surfaces
of
rocker

arm
for

damage
or
wear
If

damage
is

found

replace
them
A

faulty
pivot

must
be

replaced
together
with
its

corresponding
rocker
arm

VALVE
GUIDE

Measure
clearance
between

valve

guide
and
valve
stem
If
clearance

exceeds

designated
limit

replace
worn

parts
or
both

valve
and
valve

guide
In

this

case
it
is

essential
to
determine
if

such
a

clearance
has
been
caused

by
a

worn
or
bent
valve

stem
or
by
a
worn

valve

guide

Stem
to

guide
clearance

mm
in

Maximum
limit

of
above

clearance

mm
in
Engine
Mechanical

Exhaust
8
3
to
8
5
dia

0

327
to
0
335

4
1

3
0

I2
J
L

12

223

to
12
234

150

0
4812

to
0
4817

dia

1

P
Intake

I
I

J

10
8
0

425

S9
0

2
323
7

6
to
7

8

0
299

to
0
307
dia

1

Unit
mm

in

EM572

Fig
EM
41

Se11Jice
value

guide

In
take

valve
Exhaust

valve

0
020
to

0
053

0
0008
to
0

002

As
an

emergency
expedient
a

valve

can
be

pushed
into
valve

guide
and

moved
to
the

right
and

left
If

its

tip

deflects

about
0
2

mm
0
0079
in

or

more
it
indicates
that
the
clearance

between
stem
and

guide
exceeds
the

maximum
limit
of
0
1
mm
0
0039

in

Note
Valve
should
be
moved
in

paral

lel
with
rocker
arm

Generally
a

large
amount
of
wear
occurs
in

this

direction

Max
allowable
deflection

0
2
mm
0
0079

in

n
r

C1r
30mm
l
18Iin

r

EM115

Fig
EM

42
Mea

uring
clearance

between
valve

tern

and
valve

gu
ide
0

040
to

0
073

0
00
6
to

0
0029

0
1
0
0039
Replacement
of

valve

guide

I

To
remove
old

guides
use
a

drift

and

a

press
under

a
2
ton

pressure
or

a

hammer

Drive

them
out

from

combustion

chamber
side

toward
rocker

cover

Heated

cylinder
head
will
facilitate

the

operation

2

Ream

cylinder
head
side

guide

hole
at

room

temperature

10
6

E
e

417
5t

0

m3l
lj
10
6

O
fl

H

dl7

l
IV

II

Unit
mm
in

EM116

Fig
EM

43
Valve

guide
hole

Guide

hole
inner

diameter
an
mm
in
For

factory
standard

valve

guide
11

985
to
11

996

0
4718
to
0
4723

For
service

valve

guide

3

Carefully
press
new
valve

guide

into

valve
so
that
it
will
fit

smoothly

after

heating
cylinder
head

to
150
to

2000C

302
to

3920
F

Valve

guide
of
0
2
mm

0

0079
in

oversize

diameter
is

available
for

ser

vice

as
indicated
above

Interference
fit
of
valve

guide
to

guide
hole

0
027
to

0
049
mm

0
0011
to
0

0019
in

4

Ream
bore
with

valve

guide

press

ed
in

using
Valve
Guide

Reamer
Set

KVIOI039S0

EM
10
12

185
to
12
96

0
4797
to

0
4802

Reaming
bore

8

000
to
8

018
rnm

0
3150
to
0
3157
in

EM419

Fig
EM

44

Reaming
valve

guide

Condition

Seized
valve

seat

Excessively
worn

cylinder
and

piston

Faulty
connecting

rod

Faulty
crankshaft

bearing
Engine
Mechanical

Probable

cause

Improper
valve

clearance

Weakened
valve

spring

Thin
valve
head

edge

Narrow
valve
seat

Overheating

Over

speeding

Stuck
valve

guide

Shortage
of

engine
oil

Dirty

engine
oil

Poor

quality
of
oiL

Overheating

Wrong
assembly
of

piston
with

connecting

rod

Improper
piston

ring
clearance

Broken

piston

ring

Dirty
aii

cleaner

Mixture
too
rich

Engine
over

run

Stuck
choke
valve

Overchoking

Shortage
of

engine
oil

Low
oil

pressure

Poor

quality
of

engine
oil

Rough
surface
of

craokshaft

Clogged
oil

passage

Bearing
worn
or

eccentric

Bearingimproperly
assembled

Loose

bearing

Connecting
rod

alignment
incorrect

Shortage
of

engine
oil

Low

oil

pressure

Poor

quality
of

engine
oil

Craokshaft

journal
worn
or

out
of
round

Clogged
oil

passage
in

crankshaft

Bearing
worn

or
eccentric

Bearing
improperly
assembled

Eccentric

craokshaft

or

bearing

EM
32
Corrective
action

Adjust

Replace

Replace
valve

Reface

Repair
or

replace

Drive
at

proper
speeds

Repair

Add
or

replace
oil

Clean

crankcase

replace
oil
and
oil
niter

element

Use

right
oil

Repair
or

replace

Repair
or

replace

Adjust

Replace

Clean

Adjust

Drive
at

proper
speeds

Clean

and

adjust

Start

correct

way

Add
oiL

Correct

Use

proper
oil

Grind
and

replace

bearing

Clean

Replace

Correct

Replace

Repair
or

replace

Add
or

replace

Correct

Use

proper
oil

Repair

Clean

Replace

Correct

Replace

Conventional

COUplin9

WATER
PUMP
SPEED

F

Z

Tern

coupling

WATER
PUMP

SPEED

C0029

Fig
CO
6
Characteristic

of

Tern
coupling

INSPECTION

Check
Tem

coupling
for
oil

leakage

or
bend
of
bimetal

If
the
above

symptoms
are
found

replace
it
with

a
new
one
as
an

assembly

THERMOSTAT

A
wax

pellet
type
thermostat
is

mounted
in
the
thermostat

housing
at

the

cylinder
head
water
outlet

The
function
of
the
thermostat
is

to
control
the

flow
of
coolant
facili

tating
fast

engine
warm

up
and

regu

lating
coolant

temperature
The
ther

mostat
is

designed
to

open
and
close
at

predetermined
temperatures
and
if

not

operating
properly
should
be

re

moved
and
tested
as
described
below

REMOVAL
AND

INSTALLATION

I

Drain
coolant

partially

2
Disconnect

upper
radiator
hose
at

water
outlet

3

Remove
bolts

and
remove
water

outlet

gasket
and
thermostat
from

thermostat
housing

Fig
CO
7

Removing
therm06t
t
Cooling
System

4

After
checking
thermostat
re

install
with

a
new

housing
gasket
in

place

5
Reinstall
water

outlet

6

Replenish
coolant
and
check
for

leaks

INSPECTION

A

sticking
thermostat
will

prevent

the

cooling
system
from

functioning

properly
If
the
thermostat
sticks
in

the

open
position
the

engine
warms

up
very
slowly
If
the
thermostat

sticks
in

the
closed

position
over

heating
will
result
Therefore
the
ther
mostat
should
be

inspected
to

make

sure
that
it
is
in

good
condition

1
Measure
coolant
temperature

when
thermostat
valve
starts
to

open

2
Measure
the
maximum
lift

of

thermostat
valve

Fig
CO
S

Impecting
therm06t
t

Temperate
Frigid
Tropical

type

type
iype

Valve

opening

80
5
to
83
5
86
5
to
89
5
75

to
78

temperature

177
to
183
187
to
193

167
to
172

oC
OF

Maximum

valve
lift
8
95
8
1
00
8
90

mm
oC

in
F
0
31
203

0
31
212
0
31

194

If
thermostat
does
not

operate
at

the
above

specified

temperature
it

must
be

replaced
because
it
cannot
be

repaired

RADIATOR

The
radiator
is

a
conventional
down

flow

type
having

top
and

bottom

tanks
to

distribute
the
coolant
flow

uniformly
through
the
vertical
tube
of

radiator
core

The

radiator
filler

cap
is

designed
to

maintain
a

pre
set

pressure
0
9

kg
cm2
13

psi
above

atmospheric

pressure

The
relief
valve

consisting
of

a

blow
off

valve
and
a

vacuum
valve

helps
to

prevent
the
coolant
from

boiling
by
giving

pressure
to
it
How

ever
when

the

pressure
is
reduced

below

atmospheric

pressure
the

vacu

um
valve
allows
air

to
re
enter

the

radiator

preventing
the
formation
of
a

vacuum
in
the

cooling
system

CO
5
On
models

equipped
with
auto

matic
transmission

the
oil
cooler
is

combined
with
the

radiator
to
cool

transmission
fluid

REMOVAL
AND

INSTALLATION

Drain
coolant
into
a
clean
con

tainer

2

Disconnect
radiator

upper
and

lower
hoses
On
models
with
auto

matic
transmissions
disconnect
cooler

inlet
and
outlet
lines
from
radiator

3

Remove
fan
shroud
retaining

bolts
and

remove
fan
shroud

4

Remove
front

grille

5

Remove
radiator
retaining
bolts

and
then

remove
radiator

upward

6
Install
radiator
in
the
reverse
se

quence
of
removal
Note
the
fol

lowing

I
Insert
hoses
in

their

positions

until

they
bottom

2
Ensure
that
arrow
marks
on

hoses
are

clearly
visible
from

upper

Condition

Loss

of
water

Poor
circulation

Corrosion

Overheating

Overcooling
Cooling
System

TROUBLE
DIAGNOSES
AND
CORRECTIONS

Probable
cause

Damaged
radiator
seams

Leaks
at
heater
connections
or

plugs

Leak
at

water

temperature
gauge

Loose

joints

Damaged
cylinder
head

gasket

Cracked

cylinder
block

Cracked

cylinder
head

Loose

cylinder
head

bolts

Restriction
in

system

Insufficient
coolant

Inoperative
water

pump

Loose

fan
belt

Inoperative
thermostat

Excessive

impurity
in

water

Infrequent
flushing
and

draining
of

system

Inoperative
thermostat

Radiator
fin
choked
with
mud
chaff
etc

Incorrect

ignition
and
valve

timing

Dirty
oil
and

sludge
in

engine

Inoperative
water

pump

Loose
fan
belt

Restricted
radiator

Inaccurate

temperature
gauge

Impurity
in

water

Inoperative
thermostat

Inaccurate

temperature
gauge

CO
7
Corrective
action

Repair

Repair

Tigh
ten

Tighten

Replace

Check

engine
oil
for
contamination
and
refill

as

necessary

Replace

Check

engine
oil
in
crankcase
for

mixing

with

water

by
pulling
oil
level

gauge

Replace

Tighten

Check
hoses

for

crimps
and

clear
the

system

of
rust
and

sludge
by
flushing
radiator

Replenish

Replace

Adjust

Replace

Use
soft
clean
water
Rain

water
is
satis

factory

Cooling

system
should
be

drained
and

flushed

periodically
Permanent
anti
freeze

Ethylene
glycol
base
can
be

used

through

out
the

seasons
of
the

year
and

change

periodically
at
intervals
recommended

Replace

Clean
out

air

passage
thoroughly
by
using
air

pressure
from

engine
side
of
radiator

Adjust

Refill

Replace

Adjust

Flush
radiator

Replace

Use
soft
clean
water

Replace

Replace

Minimizes
exhaust

gas
tempera

lure
rise

2
Minimizes

horsepower
losses
re

suiting
from
air

injection
into
the

exhaust

system

3
Protects

pump
from
excessive

back

pressure

The
air

pump
relief
valve
is
installed

as
shown
in

Figure
EC

20

The

secondary
air
is

discharged

from
the
air

pump
relief
valve

to
the

dust
side
of
the
carburetor
air
cleaner

To
carburetor

air
cleaner

Secondary

air

To
carburetor

air

cleaner

J
erCOndary

r

r

EC294

Fig
EC
20
Air

pump
relief
valve
Emission
Control

System

Emargency
air
retial
valve

E
A
R
Valve

California
models

The

emergency
air
relief
valve
con

trols
the

quantity
of
secondary
air

fed

from
the
air

pump
according
to

load

condition
and
it

discharges
the
see

ondary
air
into
the

atmosphere
to

prevent
overheating
of
the

catalytic

converter

The

emergency
air
relief
valve
con

sists
of
a

diaphragm
a

spring
and

a

valve
which
is

coupled
to

diaphragm

1

Diaphragm

2

Val

3

Spring

4

Diaphragm
chamber

EC536

Fig
EC

21

mergency
air

relief
valve

OPERATION

As
mentioned

previously
there

are

two

types
of
Air

Injection
Systems

A
I

S
a

non
California

type
and
a
California

type
The
California
stand

ard

type
includes
a

system
which

controls

injection
of

secondary
air

so

as
to
assure

proper
function
of
the

catalytic
converter
and
a

system

which
controls
the

supply
of
second

ary
air
to

prevent
abnormal

tempera

tUfe
rise
in
the

catalytic
converter

The
A
I
S
consists
of
the

following

systems

L
A

system
which
allows

injection

of

secondary
air
into
the
exhaust

port

2
A

system
which

bypasses
sec

ondary
air

from
the
air

pump
relief

valve

to
the

carburetor
air

cleaner

during

high
speed
engine
operation

3
A

system
which

supplies
air

from

the
carburetor
air
cleaner

to
the
intake

manifold

by
means
of
the
anti

backfire

valve
so
as
to

prevent
after
fire

during

deceleration

4
A

system
which

controls

injection

of
the

secondary
air

by
means
of
the

air

control
valve

so
as
to
maintain
the

catalytic
converter
at
an

optimum

temperature
level
under

lightly
loaded

condi
tions

Califomia

type
only

5
A

system
which
controls
the

sup

ply
of

secondary
air

through
the
emer

gency
air

relief
vilve

io
pfevent
ab

normal

temperature
rise
of
the

cataly

tic

converter

California

type
only

A
I

S

operation
is

as
follows

I

I

t

1
r

9

I
Air

pump
6

Check
valve

I
0
L
2
Air

pump
air
deaner
7
Air

gallery
pipe

3
Air

relief
valve
8
Injection
non
e

r
4
Air
cleaner
9

Exhaust
manifold

5

Carburetor
10

Anti
backflIe
valve

EC179

Fig
EC
22
Non

California
type
A
I
S

EC
12

Floor
temparature
warning

lamp

Refer

to

Figure
EC
74

for
the

loca

tion
of
this

part

L

1t

1

RAt

Fig
EC
74
Location
of
floor

temperature
warning
lamp

INSTALLATION

To
install
reverse
the
order
of

rem
ovaL

INSPECTION

Floor
warning
temperature

system

Apply
parking
brake
Shift

gears

into
Neutral
foI
manual
transmission

and
Neutral
or
Park
for
automatic

transmission

1
Ensure
that
floor

temperature

warning

lamp
lights
when

ignition

switch
is
iumed

to
the
S

position

If

not
check

lamp
for
burned

bulbs

Replace
bulb
if
bulb
is
burned
out

If

bulb
is

not
burned
trace
wire
s

back
to

ignition
switch

Repair
or

replace
if

necessary

2
Be

sure
that
floor

temperature
is

cool
below
800C

1760Fj
before

carrying
out
the

following
procedure

I
Remove
rearseat

2

Ignition
switch
is

turned
to
the

IG

position

3
Ensure
that
floor

temperature

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
the

specifications
as

shown
in
the
table
below
Emission
Control

System

Temperature

sensing
switch

Contact
close
Temperature

warning
lamp

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
tem

perature
sensing
switch

replace
tem

perature
sensing
switch

If
con

tinuity
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
and
disconnect
floor

temper

ature

sensing
connector
The

lamp

should
remain

on
If

not
check
floor

temperature
relay
for

continuity
with

2
00

r
I

141

J

To
floor

temperatwe

warning
lamp

2
From

S

position

3
From

IG

position

4

From

ignition
switch

5
To
floor

temperature

sensing
switch
O

When
floor

temperature

warning
lamp
lights

Check
floor

temperature
warning

lamp

1

Open
or

shorj
circuit
in

wiring

harness

2

Check
fuel

system
with

regard
to

the

following
items

Refer
to

Inspec

lion
of
Fuel

System

EC
29
Floor

temperature

Below
1050C
221
OF

Above

1050C
221
OF

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
relay

When

checking
floor

temperature

relay
for
unit

remove
it
and

proceed

as
follows

1

Check
for

continuity
between

@

and

ID
Continuity
should
exist

Check
for

continuity
between

CD

and@
Continuity
should
exist

Check
for

continuity
between

CD

and

@
Continuity
should
not

exist

2

Apply
a
12

volt
doc
across

@
and

ID
to

ensure
that

continuity
exists

between

CD
and

@
and
that

con
ti

nuity
does

not
between

CD
and

@
If

test
results
dn

not

satisfy
the
above

replace
the

floor

temperature
relay

EC344

Fig
EC
75

Checking
floor
temperature
relay

1
Float
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