check engine DATSUN B110 1973 Service Owner's Guide

EMISSION
CONTROL
AND

TUNE
UP

Appearance

1
First

inspect
whether
vacuum
hoses

are
connected

to
correct

positions

2

Inspect
hoses

for
cracks
distortion
or

plugging

Checking
of
vacuum
motor

I

With

engine
shut
down

inspect
the

position
of
valve

placing
a
mirror
at
the
end
of
inlet

pipe
for

inspec

tion

The
correct
condition
of
valve
is
that
it

keeps
the

inlet
of
underhood
air

open
and
that
of
hot
air

closed

Otherwise

inspect
the

linkage
of
valve

Fig
ET
34

Inspecting
valve

position

2
Disconnect
hose
at
vacuum

motor
inlet
and
direct

ly
apply
vacuum
of
manifold
to
vacuum
motor

by

connecting
another
hose

sucking
by
mouth

may
be

substituted
for
this

process
If
underhood
air
inlet
is

closed

by
valve
valve
is
in

good
condition

Inspect

linkage
if
found
otherwise
And
then
no

defect
is

found
even
in

linkage
it

signifies
the
trouble
of

vacuum
motor

Fig
ET
35

Checking
vacuum
motor

ET
21
3
The
valve

shows
correct
condition
if
it

keeps

underhood
air
inlet
closed
when
the

passage
in

the
hose

is

stopped
by
twisting
or

clamping
it
while

applying

vacuum
If
otherwise
it
is
an
indication
of

leakage

taking
place
in
the
vacuum
motor

4
When
defect
is
found

in
vacuum

motor

through
this

check
replace
the
air
cleaner

assembly

Checking
of
sensor

I
Perform
the

engine
test

by
keeping
the

temperature

around
the

sensor
below
300C
860F
Make

sure
that

the

engine
is
cooled
down

before
the
test
is
conducted

2
Before

starting
the

engine
make
certain
that
the

valve

on
underhood
air
side

fully
opens

3
Start
the

engine
and

operate
it

at
an

idling
speed

The
valve
is
in

good
condition

if
underhood
air
side

fully
closes

immediately
after

starting

4

Carefully
watch
the
valve

to
ascertain
that

it

gradually
begins
to

open
as
the

engine
warms

up
But

when
the
ambient

temperature
is
low
it
takes

con

siderable

length
of
time

for
the
valve
to

begine
to

open

or
in
some
case
it

hardly
opens
This
should

not

however
be

regarded
as
trouble

If
the
valve
does

not

operate
satisfactorily
or
if
the

condition
of
the
valve
is

questionable
further
conduct

the

following
test

5
Remove

the
air

cleaner
cover
and

put
a
thermister

or
a
small
thermometer
as
close
to
the

sensor
as

possible
with
adhesive

tape
Install
the

air
cleaner

cover

again

Fig
ET
36

Checking
sensor

1

ENGINE

6
Start
the

engine
and
continue

idling
as
described

under

paragraphs
I
2
and
3
above

When
several

minutes
have

passed
and

the
valve
is

partially
opened

read
the

thermister
indication
It
is
correct

if
the

reading
falls
between
380C
1000
F
and

550C

1300
F

If
the

reading
is
abnormal

replace
the
sensor

7

On
the

engine
equipped
with

an
idle

compensator
as

service

option
do
as
follows
before

replacing
the

sensor

Clog
hose
on
idle

compensator
side

by

twisting
or

clamping
it

and
check
the

temperature
as

given
in

paragraphs
5
and

6
above
If
the
thermometer

shO
vs

correct

temperature

replace
the
idle

compensa

tOf
if
the

reading
is
abnormal

replace
the
sensor

CRANKCASE

EMISSION
CONTROL

SYSTEM

This

system
returns
blow

by

gas
to
both
the

intake

manifold
and
carburetor

air
cleaner
The
Posirive
Crankcase
Ventilation

PCV
valve
is

provided
to
conduct
crankcase
blow

by

gas
to
the
intake

manifold

Duirng
partial
throttle

operation
of

the

enigne

the
intake

manifold

sucks
the

blow

by
gas
through
the

valve

Normally
the

capacity
of
the

valve
is
sufficient
to

handle

any
blow

by
and

a
small

amount
of

ventilating
air

The

ventilating
air

is
then

drawn
from

the
clean
side
of

the
carburetor
air

cleaner

through
the

tube

connecting

carburetor
air

cleaner
to
rocker
cover

intu
the
crankcase

Under
full

throttle
condition
the
manifold
vacuum
is

insufficient
to
draw

the
blow

by
flow

through
the
valve

and
its
flow

goes

through
the
tube

connection
in
the

reverse
direction

In
cars
with
an

excessively
high
blow

by

some
of

the
flow

will

go
through
the
tube

connection

to

the
carburetor
air

cleaner
under

all
conditions

j

Fresh
air

Blow

by

gas

1m
Air
used
in

filtering
oil
t

2

3

4
PCV
valve

Flame

arrester

Oil
filler

cap

Baffle

plate
and

steel

net

ECOOl

Fig
ET
3
7
Crankcase
emission
control

system
at

partially
throttle

open

ET
22

EMISSION
CONTROL
AND

TUNE
UP

CD

@

Fresh
air

Blow

by

gas

Air
used
in

filtering
oil
1
PCV
valve

2
Flame
arrester

3
Oil
filler

cap

4

Baffle

plate
and

steel
net

E
C002

Fig
ET
J8
Crankcase
emission
control

system
at

full
throttle

open

Checking
and

replacing
PCV
valve

Test
PCV

valve
in
accordance
with
the

following

me
thod

With

engine
running
at
idle
remove
the
ventilator
hose

from
PCV

valve
If
the
valve
is

working
a

hissing
noise

will
be

heard
as
air

passes
through
the
valve
and

a

strong

vacuum
should
be
felt

immediately
when

a

finger
is

placed

over
the
valve
inlet
If
the
valve
is

plugged
replace
with

a

new
one
Check
for

deposit
plugging
in
the
hose
Clean
if

necessary

Intake
manifold

l

illlr
nnnl

UUUU
l
I

G

EC014

FigET
39
Cross
sectional
view

of
PCV
valve
Checking
ventilation
hoses

I
Check
hoses

and
hose
connections
for
leaks

2
Disconnect

all
hoses
and
blow
them

out
with

compressed
air

If

any
hose
can
not
be
free
of

obstructions

replace

with
a

new
one

Insure

that
the
flame
arrester
is

surely
inserted
in

the

hose

between
the
air
cleaner
and
rocker

cover

EVAPORATIVE
EMISSION

CONTROL
SYSTEM

Checking
engine
compartment
hose

connections
and
fuel

vapor
control

valves

Checking
fuel
tank

vapor
liquid
separator
and

vapor

vent
line

I

Check
all
hoses
and
fuel
tank

ftIler

cap

2

Disconnect
the

vapor
vent
line

connecting
flow

guide
valve
to

vapor
liquid

separator

ET
23

ENGINE

3
Connect
a
3

way
connector
a

manometer
and
a

cock
or
an

equivalent
3

way
change
cock
to
the

end

of
the

vent
line

4

Supply
fresh
air
into
the

vapor
vent
line

through
the

cock
little

by
little

until
the

pressure
becomes
368

mm

Aq
14
5
in

Aq

5
Shut
the
cock

completely
and

leave
it
that

way

6
After
2
5
minutes
measure
the

height
of
the

liquid

in
the
manometer

7
Variation
of

height
should
remain
within
254

mmAq
1
0
in

Aq

8
When
the
filler

cap
does
not
close

completely
the

height
should

drop
to
zero
in
a

short
time

9

If
the

height
does
not

drop
to
zero
in
a

short
time

when
the

filler

cap
is
removed
it
is
the
cause
of
the

stuffy
hose

Note
In

case
the
vent
line
is

stuffy
the

breathing
in

fuel

tank
is
not

thoroughly
made
thus

causing

insufficient

delivery
of
fuel
to

engine
or

vapor

lock

It
must
therefore
be

repaired
or

replaced

3

way

connector

Cock

Air

Manometer
Vapor
liquid

seearator

Flow

guide
valve

E

CQ29

Fig
ET
40

Checking
evaporative
emission
control

system

Checking
flow

guide
valve

I
Disconnect
all
hoses
connected
to
the

flow

guide

valve

2
While
lower

pressure
air
is

pressed
into

the
flow

guide
valve
from
the
ends
of
vent
line
of

fuel
tank
side

the
air
should

go
through
the
valve
and
flow
to

crankcase

side
If
the
air
does
not
flow
the

valve
should

be

replaced
But
when
the
air
is
blown
from

crankcase

side
it
should
never
flow

to
the
other

two
vent
lines

3
While

the
air
is

pressed
into

the
flow

guide
valve
from
the
carburetor
air

cleaner
side

it
flows
to
the

fuel

tank
side
and
or

crankcase
side

4

This
valve

opens
when
the

inner

pressure
is
10

mmHg
0
4
in

Hg
In

case
of

improper

operations
or

breakage
replace
it

From

carburetor

air
cleaner

From
fuel
tank

i

I
I

ti

i

i

1
1

i
To
ran
kcase

E
C030

Fig
ET
41
Flow

guide
valve

Checking
fuel
tank

vaCCUID
relief

valve

operation

Remove
fuel
filler

cap
and
see
if
it
functions

properly

as

follows

Wipe
clean
valve

housing
and
have
it
in

your
mouth

2

Inhale
air
A

slight
resistance

accompanied
by
valve

indicates
that
valve
is
in

good
mechanical
condition
Note

also
that

by
further

inhaling
air
the
resistance
should
be

disappeared
with
valve
clicks

3

If
valve
seems
to
be

clogged
or
if
no
resistance
is
felt

replace
cap
as
an

assembled
unit

T

1i
v

rUr1f
AlI
j

r
I
r
tLMJJl

rr
L

cc

11

J
v

II

4J
L

Valve
I

valve
seat

Spring
Valve

housing

Fig
ET

42
Fuel

filler
cap

ET
24

EMISSION
CONTROL
AND

TUNE
UP

Trouble

shooting
procedure
on

starting
circuit

Switch

on
the

starting
motor

with

light
put
on

When

light
goes
off
or
dims

considerably

a
Check

battery

b
Check
cable
for
connection

c

Check
starter
motor

When

light
stays
bright

a
Check

wiring
connection
between

battery

and
starter
motor

b

Check
starter
switch

c
Check
starter
motor

ENGINE
WILL
CRANK
NORMALLY
BUT
WILL
NOT
START

In

this
case

following
trouble
causes

may
exist
In

the
most
causes

ignition
system
or

fuel

system
is
in
trouble

Ignition
system
in

trouble

Fuel

system
in
trouble

Valve
mechanism
does
not

work

properly

Low

compression

Check

spark
plug
first
in
accordance

with
the

following

procedure

Disconnect

high
tension

cable
from
one

spark
plug
and
hold

it

about
10
rom

0
4
in

away
from
the

engine
metal

part
and

crank
the

engine

Good

spark
occurs
a
Check

spark
plug

b
Check

ignition
timing

Check
fuel

system

d
Check

cylinder
compression

No

spark
occurs
Check

the
current
flow

in

primary
circuit

Very
high
current

Inspect
primary
circuit
for
short

Check
breaker

point
for

operation

Low

or
no
current
Check
for
loose
terminal
or
disconnection

in

primary
circuit

Check
for

burned

points

Ignition
system
in
trouble

Burned
distributor

point
Repair
or

replace

Improper
point
gap
Adjust

Defective

capacitor
Replace

Rotor

cap
and
rotor
leak

Replace

ET
27

ti

ENGINE

Defective

spark
plug

Improper
ignition
timing

Defective

ignition
coil

Disconnection
of

high
tension

cable

Loose
connection
or
disconnection
in

prima

ry
circuit

Lack
of
fuel

Dirty
fuel
strainer

Dirty
or

clogged
fuel

pipe

Fuel

pump
will
not
work

properly

Carburetor

auto
choke
will
not
work

prop

erly

Improper
float
level

adjustment

Improper
idling

Dirty
or

clogged
carburetor

Damaged
anti
dieseling
solenoid

Clogged
breather

pipe

Incorrect

spark
plug
tightening
or
defective

gasket

Improper
grade
engine
oil

or

viscosity
drop

ping

Incorrect
valve
clearance

Compression
leak
from
valve
seat

Sticky
valve
stem

Weak
or

defective
valve

springs

Compression
leak
at

cylinder
head

gasket

Sticked
or
defective

piston
ring

Worn

piston
ring
or

cylinder

Troubleshooting
procedure

Pour

engine
oil
from

plug
hole
and

then
measure
cylinder
compression
Clean

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

Replace

Clean

Tighten
to
normal

torque
or
replace

spark
plug
assembly

Replace
with

proper
grade
oil

Adjust

Remove

cylinder
head
and

lap
valves

Correct
or

replace
valve

Replace
valve

springs

Replace
gasket

Replace

piston
ring

Overhaul

engine

Compression
increases
Trouble
in

cylinder
or

piston
ring

Compression
unchanged
Compression
leak
from
valve
cylinder

head
or
head

gasket

ET

28

IMPROPER
ENGINE

IDLING

Fuel

system
in

trouble

Low

compression

Others

Ignition
system
in
trouble

Engine
idle
too
fa
t

ENGINE
POWER
NOT

UP
TO
NORMAL

4
w

compression

Ignition

system
in

trouble

Fuel

system
in
trouble
EMISSION
CONTROL
AND
TUNE
UP

Clogged
or

damaged
carburetor

jets

Incorrect

carburetor

adjustment
idle

speed

idle
mixture

Clogged
air

cleaner

Defective

gaskets
of
manifolds
or

carburetor

insulator

Improper
float
level

adjustment

Incorrect
valve
clearance

Extremely
low
revolution

Incorrect
basic

ignition
timing

Incorrect
automatic

teinperature
control
air

cleaner

Defect
or
malfunction
of

ignition
system

spark
plug
high
tension
cable
breaker

point
ignition
coil
etc

Trouble
in
throttle
link
and
cable

Incorrect
throttle

opener

adjustment

Trouble
in

PCV
valve

Trouble
in
automatic

choke

Defect

or
malfunction
of

ignition
system

spark
plug
high
tension
cable

breaker

point
ignition
coil
etc

Incorrect

ignition
timing

Defective

spark
plugs

Defective
distributor

points

Malfunction
of
choke

system

Clogged
fuel

pipe

ET
29
Clean
or

replace

Adjust
idle

speed
mixture

Replace
element

Replace

gasket

Adjust

Previously
mentioned

Adjust

Adjust
idie

rpm

Adjust
ignition
timing

Adjust
automatic

temperature
control

air
cleaner

Adjust
or

replace
ignition
system

Check
throttle
link
and
cable

Adjust
throttle

opener

Replace
PCV
valve

Adjust
automatic
choke

Adjust
or

replace

ignition
system

Previously
mentioned

Adjust

Clean

adjust
or

replace
plugs

Dress
or

replace
points
Check
con

denser

Adjust

Clean

EMISSION
CONTROL
AND

TUNE
UP

Mechanical

knocking

Crankshaft

bearing

knocking

Connecting
rod

bearing

knocking

Piston
and

cylinder

noise

Piston

pin
noise

Water

pump
noise

Others
Defect
or

malfunction
of

ignition
system

spark
plug
high
tension
cable
breaker

point
ignition
coil
etc

This

strong
dull
noise
increases
when
the

engine
is
accelerated
To
locate

the

place

calise
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

knocking
and
also
increases

when
the

engine
is
accelerated
Cause
a

misfire
on
each

cylinder
and
if
the
noise

diminishes
almost

completely
this
crank

shaft

bearing
generates
the

noise

When

you
hear
an

overlapping
metalic
noise

which
increases
its

magnitude
with
the
revo

lution
of
the

engine
and

which
decreases
as

the

engine
is

warmed

up
this
noise
is
caused

by
the

piston
and
cylinder
To
locate
the

place
cause
a
misfire
on
each

cylinder

This
noise
is

heard
at
each

highest
and

lowest
dead

end
of
the

piston
To
locate

the

place
cause
a
misfire
on
each

cylinder

This

noise

may
be

caused

by
the
worn
or

damaged
bearings
or

by
the
uneven

surface

of

sliding
parts

An

improper
adjustment
of
the
valve
clear

ance

Noise

of
the

timing
chain

An

excessive
end

play
on
the
crankshaft

Remarks

Disengage
the
clutch

slightly
and

this

noise
will

stop

Wear
on
the
clutch

pilot
bushing

Remarks
This
noise
will
be
heard
when
the

clutch
is

disengaged

ET
31
Adjust
or

replace
ignition
syste
m

This
is

caused

by
the
wom
or

damaged

bearings
or

unevenly
worn
crankshaft

Renew
the

bearings
and

adjust
o

change
the

crankshaft

Check
the
lubrication

system

Same
as
the

case
of
crankshaft
bear

ings

This

may
cause
an
abnormal

wearing

of
the

cylinder
and
lower

compression

which
in

turn
will

cause
a

lower

output
power
and
excessive

consump

tion
of
oiL

Overhaul
the

engine

This

may
cause
a

wear
on
the

piston

pin
or

piston
pin
hole

Renew
the

piston
and

piston
pin
as

sembly

Replace
the

water

pump
with
a
new

one

Readjust

Adjust
the
tension

of
the
chain

Disassemble
the

engine
and
renew
the

main

bearing
bushing

Renew
the

bushing
and

adjust
the

drive
shaft

ABNORMAL

COMBUSTION

backfire
afterflfe

run
on
etc

Improper
ignition
timing

Fuel

system
in
trouble

Defective

cylinder
head

etc

EXCESSIVE
OIL

CONSUMPTION

Oil

leakage

Excessive
oil

consumption
ENGINE

Improper
ignition
timing

Improper
heat

range
of

the

spark
plugs

Damaged
carburetor
or
manifold

gasket

backfire
afterflre

Defective
carburetor

jet

Improper
function
of
the
float

Uneven

idling

Improperly
adjusted
valve
clearance

Excess
carbon
in
the
combustion
chamber

Damaged
valve

spring
backfire
afterure

Loose
oil
drain

plug

Loose

or

damaged
oil

pan
gasket

Loose
or

damaged
chain
cover

gasket

Defective
oil
seals
in
front
and

rear
of
the

crankshaft

Loose
or

damaged
locker

cover
gasket

Improper
tightening
of
oil
filter

Loose
or

damaged
oil

pressure
switch

Worn

cylinder
and

piston

Improper
location
of
the

ring
split
or
reo

versed

assembly

ET
32
Adjust
the

ignition
timing

Use

specified
spark
plugs

Replace
them
with
new
ones

Disassemble
the
carburetor
and

check

it

Adjust
the
level
and

check
the
needle

valve

Adjust

Readjust

Remove
the

cylinder
head
and

remove

carbon

Replace
it
with

a
new
one

Tighten
it

Renew
the

gasket
or

tighten
it

Renew
the

gasket
or

tighten
it

Renew
the
oil

seals

Renew
the

gasket
or

tighten
it

Do
not

tighten
excessively

Renew
the

gasket
and

tighten
it
cor

rectly

Retighten
or
renew

the
oil

pressure

switch

Overhaul
the

cylinder
and
renew
the

piston

Reassemble
the

piston
rings
correctly

ENGINE

Improper
air
fueled
mixtur

into

cylinder
walls
Check
the
fuel

system

Seizure
of

sliding

parts
Lkl
rease
of
oil

pressure
Previously
mentioned

Insufficient

clearances
Reassemble
with
the

designated
clear

ances

Overheat

Previously
mentioned

Improper
fuel
mixture
Check
the

fuel
system

SERViCE
JOURNAL
OR

6UU
ETIi
l
REFERENCE

DATE
JOURNAL
or

BULLETIN
No
PAGE
No
SUBJECT

ET
34

1t