1977 DATSUN PICK-UP fuel pump

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

Condition

Engine
hesitation

Engine
does
not

start
Engine
Fuel

Probable

cause

Main

jet
or
slow

jet
clogged

By
pass
hole
idle

passage
dogged

Emulsion
tube

dogged

Idling
adjustment
incorrect

Secondary
throttle
valve

operating

im

properly

Altitude

compensator
setting
incorrect

Cali

fornia
models

Fuel
overflows

No
fuel

Idling

adjustment
incorrect

Fast
idle

adjustment
incorrect

Damaged
anti
dieseling
solenoid

EF
37
Corrective
action

Clean

Clean
tube

Clean

Adjust

Overhaul
and
clean

Correct
H
L
lever

position

See
condition
overflow

Check

pump
fuel

pipe
and
needle
valve

Adjust

Adjust

Replace

Air
control
valve

CalifornIa
models

The
air
control
valve

con
troIs
the

quantity
of

secondary
air
fed

from
the

air

pump
according
to

engine
speed

and

load
condition
and

prevents
ex

cessive

temperature
rise
of
the

cataly

tic
converter

The
construction
is
as
shown
in

Figure
EC
16
The
intake
manifold

vacuum
and
air

pump
discharge
pres

sure

applied
to

the

diaphragm
chamber

actuate
the

valve
which
is

coupled
to

the

diaphragm
and
control
the

quanti

ty
of

secondary
air
to
be
fed
into
the

exhaust
manifold
in

response
to
the

engine
condition

c
From

air

pump

To

carburetor

air
cleaner

lr

J

EC291

Fig
EC
16
Air
control
valve

Anti
backfire
valve

This

valve
is

con
trolled

by
intake

manifold
vacuum
to

prevent
backfire

in
the

exhaust
system
at

the
ini

tial

period
of
deceleration

At
this

period
the
mixture
in
the

intake
manifold
becomes
too

rich
to

ignite
and
burn
in
the

combustion

chamber
and
burns

easily
in
the
ex

haust

system
with

injected
air
in
the

exhaust
manifold

The
anti
backfire
valve

provides
air

to
the
intake
manifold
to
make
the

air
fuel
mixture
leaner
and

prevents

backfire

A
schematic
drawing
of
the
anti

backfire
valve
is
shown
in

Figure

EC
17

The
anti
backfire
valve
inlet
is

con

nected
to
the
air
cleaner
and
the

outlet

to
the
intake
manifold

Th
correct
function
of
It
jS
valve

reduces
hydrocarbon
emission

during

aeceleration

If
the
valve
does
not
work

properly

unburned
mixture
will
be

emitted
Emission
Control

System

from
the
combustion
chambers
and

burns
with
the
aid
of
high

temperature

and

injected
air

which
causes
backfire

I
Tointake

c
manifold

vacuum

I

L

AirdisChaJ1le

I

to
mtake

manifold
From
air

cleaner

ECQ69

Fig
EC
11
Anti
back
ir
valve

Check
valve

A
check
valve
is
located
in
the
air

pump
discharge
lines
The
valve

pre

ven
ts
the
backflow
of
exhaust
gas

which
occurs
in

one
of
the

following

cases

1
When

the
air

pump
drive
belt

fails
2
When
relief
valve

spring
fails

Construction
is

shown
in

Figure

EC

18

F
rom

m

pump

1

Spring

2

Rubber
valve

3

Seat
Secondary
air

Exhaust

gas

EC292

Fig
EC
1B
Check
valve

AIr

InJaction
Into
axhaust

port

The

secondary
air

fed
from
the
air

pump
goes
through
the

check
valve
to

the
air

gallery
where
it
is
distributed
to

each
exhaust

port
The

secondary
air

is
then

injected
from
the
air

injection

nozzle
into

the
exhaust

port
near
the

exhaust
valve

n

L
y

r

V

Air
pump
relief
valve

The
air

pump
relief
valve

controls

the

injection
of
the

secondary
air
into

the
exhaust

system
when
the

engine
is

EG
11
3
I
Air

gallery

2

Exhaust
port

3
Air

jnjection
nozzle

4
Exhaust

manifold

EC293

Fig
EC
19
Air
injection
into
exhaust

port

running
at

high
speed
under
a

heavily

loaded
condition
It

accomplishes
the

following
functions
without

affecting

the

effectiveness
of
the
exhaust
emis

sion
control

system

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

DESCRIPTION

INSPECTION

CLEANING
AND
REGAP

DESCRIPTION

The

spark
plugs
are
of
the

conven

tional

type
having
14
mm
0

551
in

threads
The

spark
plug
gaps
are
1
0
to

1
1
mm
0
039
to
0
043
in
on
Cali

fomia
models
and
0
8

to
0
9
mm

0
031
to

0
035
in
on
non
California

models
The

inspection
and

cleaning

should
be
made
every
suitable
mainte

nance

period
If
necessary
replace

Note
All

spark

plugs
installed
on
an

engine
must
be

of
the
same
brand

and
the

same
number
of
heat

range

INSPECTION

L
Remove

spark
plug
wire

by

pulling
on

boot
not
on
wire
itself

2
Remove

spark
plugs

3

Check
electrodes
and
inner

and

outer

porcelains
of

plugs
noting
the

type
of

deposits
and
the

degree
of

electrode
erosion

Refer
to

Figure

EE
96

Normal
Brown
to

grayish
tan
de

posits
and

slight
electrode
wear

indicate
correct

spark
plug
heat

range

Carbon
fouled

Dry
fluffy
carbon

deposits
on
the
insulator
and

electrode
are

usually
caused

by

slow
speed
driving
in

city
weak

ignition
too
rich
fuel
mixture

dirty
air
cleaner
etc

It
is

advisable
to

replace
with

plugs

having
hotter
heat

range

Oil
fouled
Wet
black

deposits
indi

cate
excessive
oil
entrance
into

combustion
chamber

through
worn

rings
and

pistons
or
excessive
clear

ance
between
valve

guides
and

stems
If
the
same
condition
re

mains
after

repair
use
a
hotter

plug
Engine
Electrical

System

SPARK
PLUG

CONTENTS

EE
4B

EE
47

EE
47

EE
47
SERVICE
DATA
AND
SPECIFICATIONS

TROUBLE
DIAGNOSES
AND

CORRECTIONS
EE
4B

Overheating
White
or

light

gray
in

sulator
with
black
or

gray
brown

spots
and
bluish
burnt
electrodes

indicate

engine
overheating
More

over
the

appearance
results
from

incorrect

ignition
timing
loose

Normal

Overheating

EE079

4
After
cleaning
dress
electrodes

with
a
smaU
fine
file
to
flatten
the

surfaces
of
both
center
and
side

electwdes
in

parallel
Set

spark
plug

gap
to

specification

5
InstaU

spark
plugs
and

torque

each

plug
to
L5

to
2
0

kg
m

11
to
14

ft
Ib

6
Connect

spark

plug
wires

CLEANING

AND
REGAP

Clean

spark
plugs
in

a
sand
blast

type
cleaner
Avoid
excessive

blasting

Clean
and
remove
carbon
or
oxide

deposits
but
do
not

wear
away

porcelain
If

deposits
are
too
stubborn

EE
47
spark
plugs
low
fuel

pump
pres

sure

wrong
selection
of
fuel
a

hotter

plug
etc

It
is
advisable
to

replace
with

plugs

having
colder
heat

range

Ir

i

Carbon
fould

Worn

Fig
EE
96

Spark
plug

discard

plugs

After

cleaning
spark
plugs
renew

firing
surface
of
electrodes
with
me

mentioned
aboVe
Then

gap
spark

plugs
to

specified
values
with
a
round

wire
feeler

gauge
All

spark
plugs
new

or
used
should
have
the

gap
checked

and
reset

by
bending
ground
electrode

EEOBO

Fig
EE
97

Setting
park
plug
gap

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

DESCRIPTION

REMOVAL

DESCRIPTION

The
fuel
tank
is4Sliters
II

Ji
U
s

gal
9
Ji

Imper
gal
in

capacity
The

tank
unit
is

mounted
to

the

right
side

of
the
rear

floor

1
Fuel

tank

2
Drain

plug

3
Filler
tube

4

RescfYOir
tank

5
Filler
hose

6
Breather
hose

7
Ventilation
hose

8

Evaporation
hose

9
Fuel
outlet
hose
and
tube

10
Fuel

tank

gauge
unit

11

Protector

12
Bracket

13
Retainer

14
Return

tube
Engine
Control
Fuel
Exhaust

Systems

FUEL
SYSTEM

CONTENTS

FE
4

FE
5
INSPECTION

INSTALLATION
FE
6

FE
6

The
filler
shutter
is
installed
to

the

filler
tube
on
California
models

The
electric
fuel

pump
is

adopted

on
air

conditioner

equipped
models
For

the
electric
fuel

pump
refer
to

Section
EF

FE194

Fig
FE
3
Fuel
tank

FE
4

CAB
BODY
Body
Frame

Ist

mounting
2nd

mounting

1
Bolt

2

Plain

washer

3
Rubber
washer

4

Upper
rubber

5
Bottom

rubber

6
Plain
w

er

7

Upper
washer

8

Lower
washer

1st

mounting

REMOVAL

AND

INSTALLATION

Remove

battery
from

engine

compartment

2

Disconnect
oil
cooler
hoses
from

radiator
automatic
transmission

model

only

3

Disconnect
air
conditioner

tubes

from

condenser
if
so

equipped

4

Drain
water
from

cooling
system

completely
and
remove
radiator

and

condenser
if
so

equipped

5

Remove

engine
hood
from
hood

hinges
after

scribing
hood
for
rein

stallation

6
Remove

bumper
stay
from
frame

and
remove
front

bumper

7
Remove

radiator

grille

8
With
the

aid
of

Steering
Wheel

Puller

ST27
180001
remove

steering

wheel
from

steering
shaft

9

Remove

steering

gear
arm
from

steering
sector
shaft

using
suitable

puller

10

Remove
screws

securing

steering

shaft
dust

seat
and
insulator
in

posi

tion
2nd

mounting

3rd

mounting

II

Remove

steering
gear

housing

from
frame
and

pull
it
out
into

engine

compartment

12

Disconnect

speedometer
cable
at

transmission

1
3

Disconnect

carbon
canister

hoses

between

canister
to

vacuum

gallery
and
canister

to
intake

manifold

at
canister

14

Disconnect
air

pump
to
air

pump
air

cleaner
hose
at
air
cleaner

15

Disconnect
air
conditioner

hoses

from

compressor
if
so

equipped

16

Disconnect
air
cleaner

duct
from

body

17

Disconnect

Master
Vac
vacuum

hose
at
intake

manifold

18
Remove

snap
ring
and
control

lever

pin
from
transmission

striking

guide
and

remove
control
lever

19
Disconnect
fuel

hoses
at
fuel

strainer

20
Disconnect
fuel

return
hose

and

evaporation
hose
at
connectors

21
Disconnect
brake
and
clutch

tubes

from
each

master

cylinder

22
Remove

all

clips
securing
fuel

tubes
brake

tubes
and
clutch
tube
at

cab

body

BF
4
BF472A

Unit
mm
in

Fig
BF
4
Cab

body
mountings

23
Loosen
hand
brake
control
cable

at
brake
control
lever

Then
discon

nect
cable
from
dash

panel

Note

Place
blocks

against
front
and

rear
wheels
to

prevent
vehicle
from

rolling
off

accidentally

24
Free

accelerator
wire
from

car

buretor

25
Disconnect

heater
hoses
at

engine
side

26
Disconnect
wire
harnesses
from

related

engine
electrical

parts

27
Disconnect

engine
and

chassis

harnesses
at
their
connection

on

right

sidemember
near

rear

engine
mounting

member

28
Remove
six

bolts

securing
body

to
frame

29
With
the
use
of
suitable

ropes

and
an
overhead
hoist
lift
cab

body

straight
up

slowly
and

place
it
on
a

level
surface

Note
In

lifting
up
cab

body
use

care

not
to

dash
it

against

engine
or
rear

body
Cab

body

weighs
approxi

mately
220

kg
485
Ib