1977 DATSUN PICK-UP fuel pressure

Engine
Fuel

toms
and

causes
of
carburetor
troubles

and

remedies
for
them

are
listed
to

facilitate

quick
repairs

There
are
various
causes
of

engine

malfunctions
It
sometimes

happens

that
a
carburetor
which
has
no
fault
TROUBLE

DIAGNOSES
AND

CORRECTIONS

In
the

following
table
the

syml

Condition

Probable
cause

Overflow
Dirt
accumulated
on

needle
valve

Fuel

pump
pressure
too

high

Needle
valve

improperly
seated

Excessive
fuel

consumption
Fuel
overflow

Slow

jet
too

large
on
each
main

jet

Main
air
bleed

clogged

Choke
valve
does
not

open

fully

Outlet
valve
seat
of
accelerator

pump

improper

Linked

opening
of

secondary
throttle
valve

opens
too

early

Power

shortage
Main

jets
clogged

Every
throttle
valve
does
not

open
fully

Idling

adjustment
incorrect

FIICI
tr

clogged

Vacuum

jet

clogged

Air

c1eane

clogged

Diaphragm
damaged

Power
valve

operating
improperly

Altitude

compensator
setting
incorrect
Cali

fornia

models

Improper
idling
Slow

jet
clogged

Every
throttle

valve
does
not
close

Secondary
throttle
valve

operating
im

properly

Throttle
valve

shafts
worn

Packing
between

manifold
carburetor

fauJiy

Manifold
carburetor

tightening
improper

Fuel
overflow

B

C
D
D

adjustment
incorrect

Vacuum
control
solenoid

damaged

Stuck
anti
stall
dash

pot

EF

36
appears
to
have

some

problems
when

actually
the

electric

system
is
at
fault

Therefore
whenever

the

engine
is

mal

functioning
the
electrical

system

should
be
checked
rust
before

adjust

ing
carburetor

Corrective
action

Clean
needle
valve

Repair
pump

Re

place

See
condition
overflow

Replace

Clean

Adjust

Lap

Adjust

Clean

Adjust

AdjusL

pa
ir

Clean

Clean

Replace

Adjust

Correct
H
L
lever

position

Clean

Adjust

Overhaul
and

clean

Replace

Replace
packing

Correct

tightening

See
l
ondition
ov

rl1ow

Adjust

Replace

Replace

J

1
Fuel
tank

2

Fuel
f1l1er

cap
with

vacuum

relief
valve

3

Liquid
vapor

separator

4

Vapor
vent
line

5
Vacuum

signalUne

As
the
throttle
valve

opens
and

vehicle

speed
increases

vacuum

pres

sure
in

the
vacuum

signal
line
forces

rHL
JL

I

EC785

INSPECTION

FUEL
TANK

VAPOR

LIQUID
SEPARATOR

AND

VAPOR
VENT
LINE

I

Check
all
hoses
and
fuel

tank

mler

cap

2
Disconnect
the

vapor
vent

line

connecting
carbon
canister
to

vapor

liquid
separator

3
Connect
a
3

way
connector

a
Emission

Control

System

Close
at

idling

Open
at
rest

i

J

17
f

Fuel

vapor

6
Canister
purge
line

7
Throttle
valv

8

Engine

9
Carbon
canister

10
Activated
carbon

11

Screen
12
Filter

13

Purge
control
valve

14

Spring

15

Diaphragm

16
Fixed

orifice
i

j

EC784

Fig
EC
77

Evaporative
emu
ion
control

sy
tem

Fuel

vapor
flow
when

engine
i6

at
red
or

idling

the

purge
control
valve
to

open
and

admits
an

orifice
to
intake
manifold

and
fuel

vapor
is

then
drawn
into
the

I

J

o
I

Fuel

vapor

Fresh
air
intake

manifold

through
the
canister

purge
line
See

Figure
EC
7B

Fig
EC
78

Evaporative
emiuion
control

system

Fuel

vapor
flow
when

engine
i

running

manometer
and
a
cock
or
an

equiva

lent
3

way

charge
cock
to

the
end
of

the

vent
line

4

Supply
fresh
air
into

the

vapor

vent
line

through
the
cock
little

by

little
until

pressure
becomes
368

mrnH20

14
5
inH20

5
Shut
the
cock

completely
and

leave
it

unattended

6
After
2
5
minutes

measure
the

height
of
the

liquid
in
the

manometer

7

Variation
of

height
should
remain

EC
31
with
25
mmH20
0
98
inH20

8
When
filler

cap
does
not
close

completely
the

height
should

drop
to

zero
in

a
short
time

9
I
f

the

height
does
not

drop
to

zero
in

a
short
time
when
filler

cap
is

removed
it
is

the
cause
of
a

stuffy

hose

Note
In

case
the

vent
line
is

stuffy

the

breathing
in
fuel
tank
is
not

thoroughly
made
thus

causing
in

Engine
Removal

Installation

ENGINE

REMOVAL
AND
INSTAllATION

REMOVAL

INSTALLATION

ENGINE
MOUNTING
INSULATORS

REMOVAL

It
is
much
easier

to
remove

engine

and
transmission

as
a

single
unit

than

to

remove
them

separately
After
re

moval

engine
can
be

separated
from

transntission

assembly

Notes

a
Be

sure
to
hoist

engine
and

jack
up

transmission
in
a
safe
manner

b
Use

fender
cove
to

protect
vehicle

body

1
Remove

battery

2
Scribe

hood

hinge
location
for

proper
reinstallation
and
remove

hood

Note
Have

an
assistant

help
you
so
as

to

prevent
damage
to

body

3
Drain

radiator
coolant

4

Disconnect

upper
and
lower

radiator
hoses

from

engine

5

Remove

two
oil
cooler
hoses

from
lower

end
of
radiator
Auto

ma
tic
transmission

models

only

6
Remove

radiator

shroud

7

Remove
four

bolts

securing
radia

tor
and

detach
radiator

Note

Always
tighten
securing
bolt
at

upper
right
hand
side

together
with

body
harness

terminal

8

Remove
carburetor
air

cleaner
as

follows

Remove
fresh
air

duct

Remove

hot
air

duct

Loosen
air

cleaner
band

bolt
and
air

cleaner

supporting
bolts

Disconnect
air

cleaner
ta
air

pump

hose

Disconnect
air
cleaner

to
rocker

cover
hose
at

rocker

cover

Disconnect
air

cleaner

to
air

control

valve
hose
California

models

only
CONTENTS

ER
2

ER
3

ER
3
FRONT

INSULATOR

REAR

INSULATOR

TIGHTENING

TORQUE
ER
4

ER
4

ER
4

Disconnect
air

deaner
to

A
B
valve

hose

Disconnect
air

cleaner
ta

vacuum

hoses

Note

Protect
carburetor
from
dust

and

foreign
matter

by

placing
cover

over
air
inlet

opening

9

Disconnect

fuel

pump
to
fuel

fdter
hose
and
return

hose

10

Disconnect
carbon
canister

hose

on

engine
side

II

Disconnect
air

pump
air

C1eaner

to
al

p

p
hose

12

Disconnect

following
cables

wires

and
hoses

Engine
ground
cable

Accelerator
wire
at

carburetor

High
tension

cable
between

ignition

coil

and
distributor

Wire

to
distributor
at

body
ter

minal

Wire
to

oil

pressure
switch

Wires
to
thermal

transmitter

Wires
to

B
C

p
D
cut
solenoid

Non
California

models

only

auto

choke
heater
and

anti

dieseling

solenoid

Wires

to
alternator

Wires
to
starter

motor

Heater
inlet
and
outlet

hoses
if
so

equipped

Vacuum
hose
of

Master
Vac
at
in

taJce
manifold

Wires
for

back

up

lamp
switch

Cable
to

speedometer

13

Remove
transmission

control

linkage
from

transmission

Manual

transmission
models

I

Detach
rubber
boot

2
Remove
E

ring
and
control

lever

pin
from

transmission

striking
rod

guide
and

remove
control
lever

ER
2
Fig
ER
l

Automatic

transmission
models

I

Disconnect

selector

range
lever

from
manual
shaft

2
Disconnect
wires

at
inhibitor

switch
and

down
shift
solenoid

14
Air

conditioner

equipped

models
need

following

procedures

1
After

removing
flexible

hose

support
remove
four

comi
ressor

se

curing
bolts

Then
move
the

com

pressor
to

battery

support

2

Remove

vacuum
hoses
of

F
LC
D
solenoid
valve

3
Remove
F
LC

D
actuator

15
Remove
two
bolts

securing

clutch

operating
cylinder
Then
dis

connect

operating
cylinder
and

flexi

ble
tube

as
an

assembly

Manual

transmission

models

only

16
Disconnect
front

exhaust
tube

from
exhaust
manifold

17
Remove

propeller
shaft

I

Disconnect

propeller
shaft

center

bearing
bracket
from

third

crossmember

2

Disconnect

propeller
shaft
from

companion
flange
of
differential

carrier

3
Remove

propeller
shaft
from

transmission

and

plug

up
rear
end
of

extension

housing
of

transmission
to

prevent
oil

leakage

18
Attach
a
suitable
wire

or
chain

to
lift

engine

19
Remove

front

engine
mounting

bolts

at

engine
mounting
front

sup

port

Body
Electrical

System

METERS
AND

GAUGES

COMBINATION
METER

COMBINATION
METER
CIRCUIT

DIAGRAM

REMOVAL
AND

INSTALLATION

SPEEDOMETER

REMOVAL
AND

INSTALLATION

ODOMETER
SWITCH

REMOVAL
AND

INSTALLATION

FUEL
GAUGE
AND

WATER
TEMPERATURE

GAUGE

DESCRIPTION

REMOVAL
AND

INSTALLATION

OIL

PRESSURE
WARNING
LAMP

DESCRIPTION

01
L

PRESSURE
SWITCH

COMBINATION

METER

COMBINATION
METER

CIRCUIT
DIAGRAM

@

BE6828
CONTENTS

BE
14

BE
14

BE
16

BE
16

BE
16

BE
16

8E
16

BE
16

BE
16

BE
16

8E
17

BE
17

BE
17

Turn

signal

indicator

lamp

L
H

OIL

0

BEAM

BE
14
Meter
illumination

lamps

M
T

only

9

9
Turn

sq
nal

indicator

lamp

lL
J
R
H

Tj

O
iJ

I
l

g
r
i
o

I

l8

J
CHARGE

WARNING
LAMP

DESCRIPTION

HAND

BRAKE
WARNING
LAMP

DESCRIPTION

HAND
BRAKE

SWITCH

METER

ILLUMINATION

INDICATOR

AND

WARNING
BULBS

REMOVAL
AND

INSTALLATION

8ULB

SPECIFICATIONS

TROUBLE

DIAGNOSES
AND

CORRECTIONS

SPEEDOMETER

WATER
TEMPERATURE

AND
FUEL

GAUGES

OIL

PRESSURE
AND

CHARGE
WARNING

LAMPS

Voltage

regulator

TEMP

FUEL
CHG

0

BRK

C

I

Speedometer

2
Thermometer

3
Fuel
meter

4
Tachometer

Option

5

Cluster
lid

6

Speedometer
cable

7

Speed
switch

amplifier

Manual
transmission

only
BE
17

BE
17

BE
18

BE
18

8E
18

8E
18

BE
18

BE
18

BE
18

BE
18

BE
19

BE
20

Q
Speed

switch

BE856A

Fig
BE

21
Ci1
Cuit

diagram
of
combination

meter

Body
Electrical

System

Circuit

diagram
of
combination
meter

system

BATTERY

r
G
0

J

J

Z2

lIa

I

LlJ

I
Z

J

Z

a
z

J
z
Z

i

g

o
a

I
LlJ

I
ll

B

S

M

D

LIGHT

i
i
RELAY

i2i

mm

S

FROM

J

e
AMP

l1

l1

J
J

00

LlJLlJ

z
z

B

COO
CUT

n

SOLENOID

i

OIL

f
PRESSURE

SWITCH

THERMAL

a

TRANSMITTER

I
FUSIBLE

r
LINK
IGNITION
SWITCH

0
1
lOA

I

g

KG
lOA

r

I

15A

t

15A

i

7
5a

z

u

a
a
I

04LlJ

l1

J
o

02

u
3
FUEL
TANK

J

VOLTAGE

REGULATOR
HAND

BRAKE

SWITCH

J
Jon

0

j

Z

a

l

I
I

I
l

ll
Z

ll
Z

LlJ
LlJ

J
a
J
a

I
I

I
I

1

1

Zza
a

00

a
a

LlJLlJ

ll
ll
a
a
HAZARD

FLASHER

UNIT

L
J

HAZAR

D

SWITCH

I
OFF

ONI

l
I

I

I
2

I

I
3

I

14

61
I
5
6

16

9
I

76

I

FLASHER

UNIT

CJ

TO
LIGHT
IOFF

RELAY

B
l

TERMINAL

I

I

I

LIGHT

SWITCH
21

X
X

BEB57
A

Fig
BE
22
Circuit

diagram
of
combination

meter

ayatt
m
TURN

SIGNAL

SWITCH

I
L

RI

lFLA
I

IR
R

I

IR
L

I

IF
R
u

I

IF
L

u

I

FROM
L1GHT

RELAY
DIMMER

SWITCH

BE

15

Fuse

M
Body
Electrical

System

YR
Meter

voltage
regulator

Water

temperature
gauge

BE261

Circuit

diagram
of
fuel
gauge
and
water

temperature
gauge

pressure
falls
below
0
4

to
0
6

kg
cm2

5

7
to
8
5

psi
Under
normal

opera

tion
when
the

engine
is

stationary
the

ligh
glows
with
the

ignition
switch

turned

on
When
the

e

gine
is

running

and
oil

pressure
reaches
the

above

range
the
circuit

opens
and
the

light

goes
out
Ignition

switch
YW

B

1

Y

I
Fusible

link

YW

t

Thermal
transmitter
L

Fig
BE

25

OIL
PRESSURE

WARNING
LAMP

DESCRIPTION

The

engine
lubricating
system
in

corporates
an
oil

pressure

warning

lamp
which

glows
whenever

engine
oil

FUSE
BOX

SA

IGJ
G
YR

I

G

IGNITION

SWITCH

YB

I
FUSIBLE
LINK

O
J
BROWN
lffi

l

f

r@

Fuel

gauge

Fuel
tank

TO
METER
VOLTAGE
REGULATOR

TO
OTHER
WARNING

lAMPS

jt

Oil

PRESSURE

WARNING
LAhlP

YB

tl

PRESSURE

PRESSURE
FROM

BATTERY

BE263

Fig
BE

26
Circuit

of
oil

prelSure
warning
system

Fusible
link
Fuse
box

M
OIL
PRESSURE
SWITCH

To

replace
oil

pressure
switch

dis

connect

lead
wire
from
switch
termi

nal
and
unscrew
switch
from

engine

cylinder
block

Prior
to

installing
switch
to

cylinder

block
be

sure
to

apply
conductive

sealer
to
threads
of
new

switch

CHARGE
WARNING

LAMP

DESCRIPTION

The

charge
warning
lamp
glows

when
the

ignition
switch
is
set
to

ON
with
the

engine
shut
down

or

when
the

generator
falls
to

charge
with

the

engine
operated

When
the

ignition
switch
is

set
to

ON
the

charge
warning
circuit
is

closed
and
current
flows
from
the

ignition
switch
to
the

warning
lamp

and

grounds
through
the

regulator

Fig
BE
27

1
When
the

engine
is

started
and
the

generator
comes
into

operation
the

generator
output
cur

rent
N

opposes
th
current

flowing

from
the

warning
lamp
as
the
current

N
increases
the
solenoid
is
more

energized
and
the

pilot
lamp
relay

contacts
are

open
in
effect
it
oreaks

the

warning
circuit

ground
connection

and
the

lamp

goes
out
Fig
BE
27

2

Fusible
link
Fuse

box

M

From

battery

To

battery
Ig
ition

ru
nu
swllch

A
A
To

other

warning

h
To

ignition

IQlamps

i
J

r
coil
WR

t

I

j
Charge
warning
lamp

T

T

I
War

lamp
relay

J
I

Generator
v

it
ge
e

g
bt
From

battery

To

battery
Ignition

witch

J
i

L
r
t
ft
ignition

r

Glj
fCOil
WR

f

I
Warning
lamp
relay

Generator

Voltage
regulator
I
YR

Fig
BE
27
1

BE17
YR

UTO
other

warrung

lamps

Charge

warning
lamp

BE264

Fig
BE
27
2

Circuit

of
charge
warning
system

Condition

Fuel

gauge

Fuel

gauge
does
not

operate

Pointer
indicates
only

F

position
Body
Electrical

System

Probable
cause

Faulty
tank
unit
or
loose
unit

terminal

connection

pointer
indicates
a
half
level
when
a
35U

resistance
is
connected
between
tank
unit

yellow
wire

and

ground

Faulty
fuel

gauge

Poor

or
loose
cormection

Open
circuit

Faulty
tank
unit

pointer
lowers
below
E

mark
when

igni

tion
switch
Is
turned

off

Faulty
fuel

gauge

pointer
still
indicates
F

position
when

ignition
switch
is
turned
off

OIL
P

RESSURE
AND
CHARGE
WARNING
LAMPS

Condition

Oil

pressure
wamiug

lamp

Lamp
does
not

light

when

ignition
switch
is

set
to
ON

Lamp
does
not

go
out

while

engine
is

being

operated

OIarge
warning
lamp

Lamp
does
not

light

when

ignition
switch
is

set

to
ON

Lamp
does
not

go
out

when

engine
is
started
Probable
cause

Inoperative
oil

pressure
switch
or
loose

switch
terminal
connection

When
switch

yellow
black
wire
is

grounded

warning
lamp
lights

Burnt
bulb
or
loose
bulb

Open
circuit

Lack
of

engine
oil

Oil

pressure
too
low

Inoperative
oil

pressure
switch

Burnt
bulb
or
loose
bulb

Warning
lamp
does
not

light
when

voltage

regulator
white
red
wire
is

grounded

Open
circuit

Faulty

charging
system

BE
20
Corrective
action

Replace
tank
unit
or
correct
terminal

con

nection

Replace
fuel

gauge

Conect
connector
terminal

contact

Replace
tank
unit

Replace
fuel

gauge

Corrective
action

Replace
switch
OJ
correct
terminal
connee

tion

Replace
bulb
or
correct
bulb
socket

Check
oil
level
and
add
oil
as

required

Inspect
engine
oil

pressure
system

Replace
oil

pressure
switch

Replace
bulb

or
correct
bulb
socket

Inspect
charging
system

OUTLINE
OF
AIR
CONDITIONER

REFRIGERATION

SYSTEM

CONDENSER

COMPRESSOR

RECEIVER
DRYER

COOLING
UNIT

ELECTRICAL
CIRCUIT

OUTLINE
OF
AIR

CONDITIONER

The

air
conditioner
consists

es

sentially
of
a

cooling
unit

compressor

condenser
receiver

dryer
and

piping

The

cooling
unit

secured
with

three

brackets
is
a

ttached
to
the

location

occupied
by
the

package

tray

in
the
dash

panel

The

cooled
air
from
the
duct

is

directed
into
the

passenger
compart
Air

Conditioning

DESCRIPTION

CONTENTS

AC
2

AC3

AC
3

AC3

AC4

AC4

AC
5
DESCRIPTION

MAIN

RELAY

FAN
SWITCH

THERMO

SWITCH

PRESSURE
SWITCH

COMPRESSOR
RELAY

F
I
C
D

SOLENOID
VALVE
AC
5

AC
7

AC
7

AC
7

AC
7

AC
7

AC
7

ment

through
the
three

outlets
at

the

instrument

panel

The

compressor
serves
to

compress

the

vaporized
refrigerant
and
is
attach

ed

through
the
bracket
to
the
loca

tion

occupied
by
the

mechanical
fuel

pump
on
the

engine

The
condenser
cools
the

compres

sed

refrigerant
vapor
sent

by
the
com

pressor
and
is

located
on

the
front
of
the
radiator
in

the

engine
compart

ment

The
receiver

dryer

serving
as
a

reservoir

for

storage
of
the

liquid
sent

by
the
condenser
is

located
on
the

right
in
the

engine
compartment

The

piping
consists
of

two
flexible

hoses

and
five

copper
tubes
which

connect
various

components
of
the

air

conditioning
system

I

Cooling
unit

2

Expansion
valve

3
Receiver

dryer

4

Comressor
5

Condenser

6
Duct

@
Flexible
hose

@
Copper
tube

AC
2
AC724

Fig
AC
1

Cooling
system