1977 DATSUN PICK-UP fuel pump

Yellow

line

Spark
delay
valve
to

distributor

Spark
delay
valve
to
vacuum
tube

Distributor

to
vacuum
tube

Vacuum
tube
to
carburetor

Vacuum
tube
to
canister

Green
line

Anti

backfire
valve
to
intake
mani

fold

Air

control
valve
to

emergency
air

relief
valve

Intake
manifold
to
vacuum
hose

connector

Intake

manifold
to
canister

CHECKING
ENGINE

COMPRESSION

COMPRESSION
PRESSURE

TEST

I
Warm

up
engine
sufficiently

2
Disconnect

all

spark
plugs

3
Disconnect
anti

dieseling
solenoid

valve
connector

4

Properly
attach
a

compression

tester
to

spark

plug
hole
in

cylinder

being
tested
Engine
Tune

up

I

ET010
Different

compression
in
two
or

more

cylinders
usually
indicates

an

improperly
seated
valve
or
broken

piston
ring

9
Low

compression
in

cylinders
can

result
from
worn

piston
rings
This

condition

may
usually
be

accompanied

by
excessive

fuel

consumption

TEST
RESULT

If

compression
in

one
or
more

cylinders
is
low

pour
a
small

quantity

of

engine
oil
into

cylinders
through

the

spark
plug
holes
and
retest
com

pression

I

If

adding
oil
increases
the
com

pression
pressure
the
chances
are
that

rings
are

faulty

2

If

pressure
stays
low

probable

cause
is

that
valve
is

sticking
or

seating

improperly

3
If

cylinder
compression
in

any

two

adjacent
cylinders
is

low
and
if

adding
oil
does
not

help
the

compres

sian
there
is

leakage
past
the

gasket

surface

Oil
and
water
in

combustion
cham

bers

can
result
from

leakage

IGNITION
AND

FUEL
SYSTEM
Fig
ET
10

Teding

compression

pressure

5

Depress
accelerator

pedal
to

open

throttle
and
choke
valves

Note
Do

not

pump
pedal

6
Start

engine
as

quickly
as

pos

sible

7

Compression
pressure

kg
cm2

psi
at

rpm

Standard

12
0

171
350

Minimum

9

0
128
350

8

Cylinder
compression
in

cylinders

Should
not
be
less
than

80
of

highest

reading

CONTENTS

CHECKING
BATTERY
ET
9

CHECKING
DISTRIBUTOR
CAP
ROTOR

CHECKING
AND

ADJUSTING
IGNITION
AND
CONDENSER
ET
11

TIMING
ET
10

CONDENSER
ET
11

ADJUSTING
IGNITION
TIMING
ET10

ADJUSTING
CARBURETOR
IDLE
RPM

CHECKING
AND
REPLACING
SPARK
PLUG
ETlO
AND
MIXTURE
RATIO
ET

11

CHECKING
DISTRIBUTOR
OPERATING
IDLE

LIMITER
CAP
ET
12

PARTS
AND

IGNITION
WIRING
ETlO
CHECKING
CARBURETOR
RETURN
SPRING
ET

12

BREAKER
POINTS

lNon
California
models

ET
10
CHECKING
CHOKE
MECHANISM

AI
R

GAP
lCalifornia
models
ET11
Choke

plate
and

linkage
ET13

DISTRIBUTOR
ET
11
CHECKING
FUEL

LINES

IGNITION
WIRING

ET
11
Hoses

pipings
connections
etc

ET
13

REPLACING
FUEL
FILTER
ET
13

CHECKING
BATTERY

Check

electrolyte
level
in

each
bat

tery
cell
I
Unscrew

each
filler

cap
and

inspect
fluid
level
If
the
fluid
is
low

add
distilled
water
to

bring
the
level

up
approximately
10
to
20
mm
0
39

H
9
to
0
79

in
above
the

plates
Do
not

overfill

2
Measure
the

specific
gravity
of

battery
electrolyte

CHECKING
CHOKE

MECHANISM
Choke

plate
and

linkage

1
Check
choke

valve
and
mech

anism

for
free

operation
and
clean
or

replace
if

necessary
A
binding
can

result
from

petroleum

gum
formation

on
choke
shaft

or
from

damage

2

Check
bimetal
cover

setting

Index
mark

on
bimetal

cover
is

usually

set

at
center
of
scale

Note

Always
align
the
index

mark
on

bimetal
cover
with
the
center
index

mark
on
choke

housing

3

Every
day
before

starting
engine

depress
the
accelerator

P
dal
to
see
if

choke
valve
is
closed

automatically

If
it
fails
to
be
closed
the

chances

are
that
link
movement
is
unsmooth
Engine
Tune

up

or
that
bimetal
is

out
of
order
Refer

to
Carburetor
in
Section
EF

CHECKING
FUEL

LINES
Hoses

pipings
connections

etc

Check
fuel
lines
for

loose
con

nections

cracks
and

deterioration

Retighten
loose
connections

and
re

place
any
damaged
or
deformed

parts

REPLACING
FUEL

FILTER

Check
for
a

contaminated
filter
and

water

deposit
All

engines
use
a

replaceable

cartridge
type
fuel
filter
as
an
as

sembly

@

Fig
ET

19
Fuel

filler
ET011

EMISSION
CONTROL
SYSTEM

CHECKING
CRANKCASE
EMISSION

CONTROL
SYSTEM

REPLACING
P
C
V
VALVE
AND

FILTER

CHECKING
VENTILATION
HOSE

CHECKING
EXHAUST
MANIFOLD
HEAT

CONTROL
VALVE

CHECKING
SPARK
TIMING

CONTROL

SYSTEM

SPARK
DELAY
VALVE

Automatic
transmission
models

only

INSPECTION

CHECKING

AUTOMATIC
TEMPERATURE

CONTROL
AIR

CLEANER

OPERATING
PRESSURE
OF

BOOST

CONTROLLED
DECELERATION
DEVICE

B
CD
D
I
ADJUSTMENT

CHECKING
B
C
DD
CIRCUIT

WITH

FUNCTION
TEST

CONNECTOR

CHECKING

CRANKCASE

EMISSION

CONTROL

SYSTEM

REPLACING
P
C
V
VALVE

AND
FILTER

Check
P

C
V

valve
in

accordance
CONTENTS

ET
13

ET
13

ET
14

ET
14

ET
14

ET
14

ET
15

ET
15

ET
17

ET
17
ADJUSTMENT
OF
SET
PRESSURE
OF

BOOST

CONTROLLED
DECELERATION

DEVICE
B

CD
D

CHECKING
B
C
D
D
SOLENOID
VALVE

CHECKING
AMPLIFIER
Manual

transmission
models

REPLACING
AIR
PUMP
AIR
CLEANER

ELEMENT

CHECKING
EXHAUST
GAS
RECIRCULA

TION
E
G
R
CONTROL
SYSTEM

CHECKING
EVAPORATIVE
EMISSION

CONTROL

SYSTEM

CHECKING
CATALYTIC
CONVERTER

INSPECTION

CHECKING
FLOOR
TEMPERATURE

WARNING
SYSTEM

INSPECTION

with
the

following
method

With

engine
running
at

idle
remove

ventilator
ose
from
P
C
V

valve
If

the
valve

is

properly
working
a

hissing

ET
13
ET
18

ET
20

ET
20

ET
20

ET
20

ET
22

ET

23

ET
23

ET

23

ET
23

noise
will
be

heard
as
air

passes

through
the

valve
and
a

strong
vacuum

should
be
felt

immediately
when

a

finger
is

placed
over
valve
inlet

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

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

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

Condition

POOR
FUEL
ECONOMY

Se
the

xplanation

of
the
pow
r

dec

Oth
n

PROBLEM
IN

OTHER

FUNCTIONS

D
cr
d

oil

p
ssure

Excessive
wear
on
the

sliding

parts

Scuffing
of

sliding

parts

Floor

temperature
too

high
California

only
Engine
Tune

up

Probable
cause

Exceeding
idling
revolution

Inoperative
acceleration
recovery

Fuel

leakage

Malfunction
of
B

C
D
D

Malfunction
of
A
r
C
air

cleaner

Inadequate
oil

quality

Overheat

Worn

oil

pump
regulator
valve

Functional
deterioration
of
oil

pump

Blocked
oil
f1lter

Increased
clearance
in
various

sliding
parts

Blocked
oil
strainer

Inoperative
oil

gauge
pressure
switch

Oil

pressure
decreases

Improper

quality
or
contamination
of

oil

Damaged
air
cleaner

Overheat
or
overcoal

Improper
fuel
mixture

Decrease
of
oil

pressure

Insufficient
clearances

Overhea
t

Improper
fuel

mixture

Problem
in

fuel

system
Refer
to

Inspec

tion
of
Fuel

System

Problem
in

ignition
system
Refer
to
In

spection
of

Ignition
System

ET33
Corrective
action

Adjust
it

to
the

designated
rpm

Adjust
it

Repair
or

tighten
the
connection
of

fuel

pipes

Adjust

Check
and

replace

Use
the

designated
oil

Previously
mentioned

Disassemble
oil

pump
and

repair
or
renew
it

Repair
or

replace
it

with
a

new
one

Renew
it

Disassemble
and

replace
the
worn

parts
with

new
ones

Oeanit

Replace
it
with
a
new
one

Previousiy
mentioned

Exchange
the
oil
with

proper
one
and

change
element

Change
elemen
t

Previously
mentioned

Check
the
fuel

system

Previously
mentioned

Readjust
to
the

designated
clearances

Previously
mentioned

Check
the
fuel

system

Check
and

repair

Check
and

repair

r

I

I

PRELIMINARY
CLEANING
AND

INSPECTION

DISASSEMBL
Y

PRELIMINARY

CLEANING
AND

INSt

ECTION

Before

disassembling

engine
note

the

following

I
Fuel

oil
or
water

may
leak

past

cylinder
head
and
block
Prior
to

disassembling
check

cylinder
head

1
1ltermal
vacuum
valve

2
Check

valve

3
Altitude

compensator

in

air
cleaner

4
Air

gallery
pipe

S

Auto
choke

6
Automatic

temperature

control
air

cleaner

7
Anti
8ackfire
valve
A
B

valve

8
Boost
Controlled

Deceleration

Device
Bee
D
D

9
P
c
v

valve

to
Air
relief
valve

11
E

G
R

control
valve

12
B
C
D
D

control
valve
and

solenoid
valve

13

Emergency
air

relief
valve

14
Air

pump
air
cleaner

IS
Carbon
canister

16
Air
control

valve

11
Air

pump
Engine
Mechanical

ENGINE

DISASSEMBLY

CONTENTS

EM
4

EM
4
PISTONS
AND
CONNECTING
RODS

CYLINDER

HE
AD
EM
7

EM
7

front
chain

cover
oil

pan
and
oil

filter

gaskets
lInd
crankshaft
and
water

pump
seals
for

signs
of

leakage
past

their

gasketed
surfaces

2
Check
carburetor
and

fuel

pump

for
condition
fuel
hoses
for

deteriora

tion
cracks

or

leakage
of
fuel

past

their

jointed
or
connected

surfaces

Fig
EM

0
Emiuion
control
devic
s

California
mod
18
E
T366

3
Remove

carburetor
air

cleaner

Remove
fresh

air
duct

Disconnect
hot
air
duct
from

air

cleaner

Disconnect
air

cleaner
to
air

pump

hose
at
air

cleaner

Disconnect
air

cleanef
to
rocker

cover

hose
at
rocker
cover

Disconnect

air
cIeaner

to
air

con

trol

valve
hose
at
air

cleaner
Cali

fornia

models

only
Disconnect
air

cleaner
to
A

B
valve

hose
at
air

cleaner

Disconnect
air

cleaner
to

related

part
vacuum
hoses
at
air

cleaner

Loosen
air

cleaner
band
bolt
and

remove
carburetor
air

cleaner
as

sembly
from

carburetor

4

Plug
up
carburetor
air

horn

to

prevent
entry
of

foreign
matter

5

Remove

alternator
drive

belt

alternator
and

alternator
bracket

EM
4
6

Remove
air

pump
drive

belt
cool

er

compressor
and
idler

pulley
if

so

equipped

7
Remove
starter
motor
from
trans

mission

8

Visually

inspect
cylinder
head

cylinder
block
rocker
C
Ner

front

chain
cover
oil

pan
and
all
other
outer

parts
for
oil
water
and
fuel
leaks

breakage
or

missing
parts
such

as
bolts

and
nuts

9

Check

piping
and
electrical
cir

cuits
for
deterioration

breakage
fit

tings
discontinuity
or
insulation

DISASSEMBLY

To

remove

engine
from
vehicle

refer
to

the
instructions
under
the

Engine
Removal

and
Installation

ER
section

I

Remove
transmission
from

en

gine

2
Remove

clutch

assembly
from

flywheeL

3

Thoroughly
drain

engine
oil
and

coolan
t

by

removing
drain

plugs

Store

engine
oil
and

coolant
if

they

are

to
be

used

again

4
Place

engine
assembly
on

engine

stand

I

Remove

cooling
fan

2

Remove

right
engine

mounting

bracket

3

Remove
oil
filter
with
Oil

Filter

Wrench
STI9320000

4

Remove
oil

pressure
swi

tch

5

Install

engine
attachment
to

cylinder
block

utilizing
bolt

holes
in

alternator

bracket
and

water
drain

hole

6
Set

engine
on
stand

Engine
Attachment

ST05260001

Engine
Stand

ST050I

SOOO