ECO DATSUN PICK-UP 1977 Workshop Manual

CLEANING
AND

INSPECTION

Dirt

gum
wuler
or
l
arbon
con

taminatiun
in

or
on
exterior

moving

parts
of
a

arburctor
arc
often

respon

sihk
for

unsatisfactory
performance

For
this

reason
efficient
carbutetioll

dcpends
upon
careful

cleaning
and

inspection
while

servicing

I

Blow
all

passages
and

castings

with

compressed
air

and
blow
off
all

parts
until

dry

Note
Do
not

pass
drills

or
wires

through
calibrated

jet
or

passaaa

as
this

may
enlarge
orirlce
and

seriously
affect
carburetor
calibrs

lion

2

Check
all

parts
for
wear
If
wear

is

noted
damaged

parts
must
be
re

placed
Note

especially
the

following
Engine
Fuel

I
Check
float
needle

and
seat
for

wear
If
wear
is

noted

assembly
must

be

replaced

2
Check
throule
and
choke
shaft

bores
in
throtlle
chamber
and
choice

chamber
for
wear
or

out
of
roundness

3
Inspect
idle

adjusting
needle
for

burrs
or

ridges
Such
a

condition
re

quires
replacemen
1

3

Inspect
gaskets
0
see
if

they

appear
hard
or
briUle
or

if

edges
are

torn
or
distorted
If

any
such
condi

tion
i
noted

they
must
be

replaced

4
Check
filter
screen
for
dirt
or
lint

Clean
and
if
screen
is
distorted
or

remain

plugged
replace

5
Check

linkage
for

operating

condition

6

Inspect
operation
of

accelerating

pump
Pour
f
el
into

jloat
chamber

and
make
throtlle
lever

operate
Check

condition
of
fuel

injection
from

the

EF
34
accelerating
nowe

7

Push
connecting
rod

of
dia

phragm
chamber
and
block

passage
of

vacuum
with

finger
When

connecting

rod
becomes
free
check
for

leakage
of

air

or

damage
to

diaphragm

Jets

Carburetor

performance
depends

on

jet
and
air
bleed
That
is

why

these

components
must
be

fabricated

with
utmost
care
To

clean
them

use

cleaning
solvent
and
blow
air

on
them

Larger
inner
numbers

tamped
on
the

jet
indicate

larger
diameters
Ac

cordingly
main
and

slow

jets
with

lalger
nUmbers

provide
richer
mixture

the
smaller
the
numbers
the
leaner
the

mixture
Conversely
the
main
and

slow
air
bleeds

through
which
air
to

passes
through
make
the
fueLleaner
if

they
bear

larger
numbers
the
smaller

the
numbers

the
richer

the
fuel

Engine
Fuel

SERVICE
DATA
AND
SPECIFICATIONS

Airclelllcr

Ail
control
val

partially

opem

Air
ntrol
valve

fuUy
opens

Idle

ompensatoI

partially
opens

Hi
mettiNo

l

Bi
metal
No
2

Idle

ompen
tor

fully
opens

Bi
metal

No
1

Hi
metd
No
2

Fuels
Stem

Fuel

prtuure

Fuel

pump
apacHy

C
rbu
tor

C
rbu
tor

type

Carburetor
model
Oc

oF

oCe
F

oCe
F

Oc
OF

kpJcm2
poi

US

pt
min
at

rpm

Outlet
diameter

Venturi
diameter

Main

jet

Main
air
bleed

Slow

jet

Power
val

Float
level
U

fuel

preuure
rom
in

mm
in

mm

in

kg
cm2

psi

Adjustment

Engine
idling
Ignition
timing
Idle

speed
CO
at

mloro

Fuel
level

adjustment

Gap
between
Ive
stem
and
noat
at
mm

in

H

H

h

Fast
idle

adjwtmcnt
Fast
idle
earn

tint

step

Gap
between
throttle
IYe
and
carburetor

body

mm
in

Vacuum
break

adjustment

Gap
between
choke
alve
and
carburetor

body

mm

in

Choke
unloadel

adjusttncnt

Gap
between
choke
alw
and
carburetor

body

rom
in

Bi

metalsettinl

Bi
metal
resistance
at
2Ioe
700F

n

Bi
metalsettina

lnterloc
k

opcnina
of

primary
and

secondary

throtUc
valves
mmOn

Duh
pot

adjustment
without
loadin

I
m

Anti
diclClinasolenoid
valV
C

tiahtenina
torque

ka
m

in
lb

a
c
D
D
set

p
JSure

0
m
sea

level
and
760

mmHg

30
inlla
atmospheric
pressure
J
mmHa
inHg

R
C
D
D

tiahteninl
torque
kg
m

n
b
Nl
n
California
modell

Manual
transmiSsion

I
Automatic
transmission
California
modeb

Manual
transmission

I
Automatic
transmission

30
to
54
86
to
129

above

55
131
30
to
54
86
to
129

above
55

131

60
to
70

140
to
158

70
to
90

158
to
194
60
to
70

140
to
158

70
to
90

158
to
194

above
70

158

above
90

194
above
70

158

above
90

194

0
21
to
0
27
2
99
to
3
84

t
OOO

2
i
I
OOO
0
21
to
0
27
2
99
to

3
84

1
000
2
i
I
OOO

Strombcra
type

OCH340
7A
DCH340
48A
Stromt
rg

type

DCH34Q
45B
DCH340
46A

Primary
Secondary
Primary
Secondary
Primary
Secondary
Primary
Secondary

30
I8t

340
339
30
1
181
34
1
339
30
1
181

34
1
339
30
1

181
34
1
339

24
0
945

310
220
24
0
945
31
1
220
24
0
945
31
1
220
24
0
945
31
1
220

199
1160
199
1160
1101
1160
101

1160

170
160
170
160
170
60

170
1
60

148
1100
148
1100
148
1100
148
180

143
143
140
140

23
0
906
23
0
906
23
0
906
23

0
906

0
17
2
408
0
17
2
40B
0
17
2
408
0
17
2
408

1201750

rpm
CO

2
1
120

650

rpm
0

100
750rpm
C02
t
1
120
650

rpm
0

position
CO

2
t
1

position
CO
2
t
1

7
2

0
283
7
2
0
283
7
2
0
283
7
2
0
283

23
0
906
23

0
906
23
0
906
23
0
906

1
3
to
1
7
1

3
to

1
7
1
3
to

1
7
1
3
to
1
7

0
051
to
0
067
0
051
to
0

067
0
051
to
0
067
0
051
to
0
067

1
33
to
1
47
1
58
to
1
72
1
33
to

1
47
1
58
to
1
72

0
0524
to
0
0579
0
0622
to

0
0677
0
0524
to
0
0579
0
0622

to
0
0677

1
42
0
056
1
42
0
056
1
42
0
056
1
5
0
059

2
45
0
096
2
45
0
096
2
4
0
096
2
45
0
096

3
7
to

8
9
3
7
to
8
9
3
7
to
B
9
3
7
to
8
9

Center
of
the
ndex
mark
Center
of
the
index
mark

7
38
0
291
7
38
0

291
7
38
0

290
7
38
0
291

1
900
to

2
100
1
650
to

1
850
1
900
to
2
100
1
650
to

1
850

180
to
350

156
to
304
180
to
350

156
to
304
180
to
350

156
to

304
180
to
350

156
to
304

510
to

550
490
to

530
510
to
550
490
to
530

20
1
to
21
7
19
3
to

20
9
20
1
to
21
7
19
3

to
20
9

20
to
40

17
4
to
34
1
20

to
40

11
4
to
34
7
20
to
40

17
4
to
34
7
20
to

40
17
4
to
34
1

EF
35

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

Emission
Control

System

EARLY

FUEL

EVAPORATIVE

SYSTEM
E

F
E

DESCRIPTION
spring
and

counterweight
which
are

assembled
on
the

valve
shaft

projecting

to
the

rear
outside
of
the
exhaust

manifold
The

counterweight
is
se

cured
to
the
valve
shaft
with

key
bolt

and

snap
ring
EC
4
A

control
valve
welded
to

the

valve
shaft
is

wtalled
on
the

exhaust

manifold

through

bushing
This
con

trol

valve
is

called
Heat

control

valve
The
heat
control

valve
is

ac

luated

by
the

coil

spring
thermostat
Construction
of
the

early
fuel

evap

orative

system
is

shown
in

Figure

r
I

1

@

rW

9

Sc
w

10
Thennostat

spring

11

Coil
spriiig

12
Control
valve
shaft

13
Heat
control

valve

14

Bushing

15

Cap

16
Exhaust
manifold
1
Intake
manifold

2
Stove

gasket

ManifoktstOve

4
Heat
shield

plate

5

Snap
ring

6

Counterweight

7

Key

g

Stoppel
pin

EC532

Fig
EC
4
Early
Fuel

Evaporutive
tem
E
F
E

The

early
fuel

evaporative
system
is

provided
with
a
chamber
above

a

manifold
stove
moonted
between
the

intake
and
exhaust

manifolds

During

engine

warming
up
air
fuel
mixture
in

the

carburetor
is

heated
in
the
cham

bet

by
exhaust

gases
This
results
in

improved
evaporation
of

atomized
fuel

droplets
in
the
mixture
and
in

smaller

content
of

hydrocarbons
He
in
the

exhaust

gas
especially
in

cold
weather

operation

The
exhaust

gas
flow
from
the

engine
is

obstructed

by
the
heat
con

trol

valve
in
the

exhaust
manifold
and
is

changed
in

direction
as
shown

by

the
solid

lines
in

Figure
EC
4
The

exhaust

gas
heats
the
manifold
stove

Open
close

operation
of
the

heat

control
valve
is
controlled

by
the

counterweight
and
thermostat

spring

which
is
sensitive
to
the

ambient
tem

perature
around
the

exhaust
manifold
With
this
condition
the

heat
control

valve
is
in

the

fully
closed

position

obstructing
the
flow
of

exhaust

gas
As

engine
tempera
lure

goes
up
and

the

ambient

temperature
becomes

high

enough
to
actuate
the
thermostat

spring
the

counterweight
begins
to

rotate
clockwise
and

again
comes
into

con

tact
with

the

stopper
pin
With
this

condition
the

heat
control
valve
is
in

the
full

open
position
and
exhaust

gas

passes
through
the
exhaust
manifold
as

shown

by
the
dotted

lines
in

Figure

EC
4
without
heati

ng
the
manifold

stove
OPERATION

The

counterweight
rotates
counter

clockwise
and

stops
at

the

stopper
pin

mounted
on
the
exhaust

manifold

while

the

engine
temperature
is
low

EC
6

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

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

The
non
California

type
operates
as

follows

secondary
air
is
sucked

through
the
air

pump
air

cleaner
into

the
air

pump
driven

by
the
crank

pulley
It
is

then

discharged
through

the

check

valve
to

the
air

gallety
where

it
is

distributed
to
each

exhaust

porL

The

secondary
air
is
then

injected

from
the

injection
nozzle

into
the

exhaust

port
near
the
exhaust
valve

The
air
relief
valve

opens
only
when

the

discharge
pressure
of
the
air

pump

surpasses
the

spring
force
of
the
air

relief
valve

during
high
speed
opera

tion

When
the
air

relief
valve

opens

the

secondary
air
is

discharged
in
to

the

carburetor
air
c1eaner

The
anti

backfire
valve

opens
when

the
intake
manifold
vacuum

reaches
a

predetermined
value

during
decelera

tion

and

permits
fresh
air
to
now
into

the
intake

manifold
from
the
air

cleaner

f

I

Jl

rn
l

I
Air

pump

2
Air

pump
air

cleaner

3

Emergency
air

relief
valve

4

Air

relief
valve
riu

Qj

j

I

@
Emission
Control

System

To
intake

manifold

The
California

type
includes
in

addition
to
the

components
of
the

non
California

type
an

air

control

valve

and
an

emergency
air
relief
valve

The
air

control
valve

opens
when

the
sum
of
the
air

pump

discharge

pressure
and

the
intake

manifold
vacu

um

applied
to
the

diaphmgm
reaches
a

predetermined
level
and

discharges

the

secondary
air
into
the

air
cleaner

When
the

pressure
becomes
low
the

valve
doses

with
the

spring
force
of

3

5
Air

cleaner

6

Check
valve

7

Air

gallery

pipe

8

Carburetor

EC

13
To

intake

manifold

Air

diSlcharge
to

intake
manifold

Secondary

air

EC297

Fig
EC

23

Operation

of
A

B
lve

the
air
control
valve

and

stops
dis

charging
the

secondary
air

F
igure

EC

25

When
the

intake
manifold

vacuum

applied
to
the

diaphragm
reaches

a

predetermined
level
E
A

R
valve

operates
to

discharge
the

secondary
air

into
the

atmosphere
When
the

pres

sure

becomes

high
the
valve

closes

by

spring
tension
of
E
A
R
valve

and

stops

discharging
the

secondary
air

fl

t

9
Air
control
valve

10

Injection
nozzle

II
Exha
l
t

manifold

12
Anti
backfire
valve

EC780

Fig
EC
24

California

type
A
I

S

j

EC231

Thermal

vacuum
valva
o

o

m
Emission

Control

System

0

o

o

o

l

l
@

The
thermal
vacuum
valve

is

mounted
in

the

engine
thermostat

housing
It

detects

engine
coolan
t

tem

perature
by
means
of
a

built
in

bi

metal
and

opensor
closes
the

vacuum

passage
in
the

thermal
vacuum

valve

mt

li

t

00
t

EC232

Fig
EC
54
Thennal

vacuum
valve
To
E

G
R
control
valve

From
carburetor

1

Spring

2
Bi
metal

3

O

ring

E
G
R

warning

system

The

E
G
R

warning
system
install
1

Diaphragm
spring

2

Diaphragm

3
Valve
shaft

4

Valve

5
Valve

Seat

6
Valve
cham
ber

Fig
EC
53
E
G

R
control
value

When
the

vacuum

passage
is

open
the

carburetor
suction

vacuum
is

applied

to
the

diaphragm
of
the
E
G
R

con

trol
valve
to

actuate
the

taper
valve

connected
to
the

diaphragm

theconsiiiictlo

nlie
thermal

vacuum
valve
is

shown
below

ed

independently
of
the

E
G
R

con

trol

system
monitors

the
distance
the

car
has
travelled
and

indicates
when

EC
22
the
E

G
R

control

system
must
be

checked

The
E
G
R

warning
system
consists

of

an
odometer
switch

detector
drive

counter
E

G
R

warning

lamp
and

harnesses

When
the

earn
in
the

odom

eter
switch
connected
to

the

speed

ometer
turns

once
for

each
OAkm
4

mile
the

contact

point
of
the
elec

trica
circuit
closes

allowing
electric

current
to
flow

through
the

magnet

coil
of

the
detector

drive
counter

Thus

energized
the

magnet
coil
ac

Wates

the
latchet
to

turn
the
c
unter

wheel

by
one

pitch
When
the

number

of

counts
reaches
50
000
the
latchet

drops
in

a

groove
provided
on
the

periphery
of

the
counter
wheel
to

activate

the
detector

drive
counter

switch

Then
the

E
G
R

warning

lamp

comes
on

indicating
that
the
E
G
R

control

system
Should
be
checked

The

detector
drive

coun
teT
is

equip

ped
with
an
odometer
which

can
tell

when
to
service

the
E

G
R
contr0
I

system

After

completing

periodic
check

reset
the
odometer
to

zero
by
hand

proceeding
as
follows

1
Remove

grommet
installed
on

the
side

surface
of

detector
drive

counter
unit

2
insert

a
bar

or
a
screwdriver

tip

into
the

hole
from

which

grommet
has

been

removed
and

press
down
knob

provided
in

the
detector
drive
counter

for

resetting

The
E

G
R

warning

lamp
comes

on

under
the

following
circumstances

1
When
the
number
of

counts
has

reached
50
000
In
this

case
the

lamp

indicates
that
E

G
R

control

system

must
be
checked

2
When

operating
starter
motor

Notes

a
It
is

an
indication
of

problem
in

the

E

G
R

warning
lamp
or

problems

in
the

point
or
in
the
harnesses
if

the

lamp
does
not

light
at

50
000

counts

b

The
E

G
R

warning
system
is

mounted

on
all
620
models

except

those

bound
for
California
and

Canada

Ignition
Switch
Position
START

Detector
Drive

Counter

E
G
R

Warning
Lamp
ON

b
After

completing
inspection
of

E

G
R

control
system
be

sure
to

reset

odometer
of
detector
drive

counter
to

zero

c
This
item

applies
to
all
620
models

except
those
bound
for
California

and
Canada

3

With

engine
stopped
inspect

E
G
R
control
valve
for

any
indication

of

binding
or

sticking
by
moving
dia

phragm
of
control
valve

upwards
with

a

finger

2
When

engine
coolant

tempera

ture
is

high

I
Make

sure
that
E

G
R

control
valve

operates
when

engine
speed
is
in

creased
from
idling
to
3
000
to

3
500

rpm
Place
a

fmger
on
the

diaphragm
of
E
G
R
control

valve

to
check
for
valve

operation

2
If

E
G
R
control
valve
does
not

operate
check

as
follows

Disconnect
one
end
E

G
R
control

valve
side
of
vacuum
hose
connect

ing
thermal
vacuum
valve
to
E
G
R
Emission
Control

System

ON

Below

50
000
counts
Above

50
000
counts

OFF
ON

4
With

engine
running
inspect

E
G
R

control
valve
and
thermal
vacuo

um
valve
for
normal

operation

1
When

engine
coolant

tempera

ture

is
low

Make

sure
that
E
G
R

control
valve

does
not

operate
when

engine
speed
is

increased
from

idling
to
3
000
to

3
500

rpm

Place
a

fmger
on
the

diaphragm
of

E
G
R
control
valve
to

check
for
valve

operation

EC253

Fig
EC
62

Checking
E
G
R
control
valve

control
valve

Increase

engine
speed
from

idling
to

3
000
to
3

500

rpm

Make
su
re
that
thermal
vacu
um

valve
is

open
and
that

carburetor

vacuum
is

present
at
the
end

E

G
R
control

valve
side
of

vacu

um
hose

If
vacuum
is
weak
or

not

present
at

all

replace
thermal
vacuum
valve
If

vacuum
is

present
replace
E
G

R

control
valve

EC
25
EC254

Fig
EC

63

Checking
lhermal

vacuum
valve

If

any
difficulty
is
encountered
in

judging
the
condition
of

any

compo

nent

during
above

inspection
check

the

questionable
component
independ

ently
as

follows

E
G
R

control
valve

Dismount
E

G
R

control
valve

from

engine

I

Apply
vacuum
to

E
G
R

control

valve

referring
to
the

following
figure

If

the
valve

moves
to
full

position
it
is

normal

E
G
R

control
valve
will
remain

open
for
more

than
30

seconds
after

vacuum
has
cut

off

la

ET152

Fig
EC
64

Checking
E
G
R

control

ualue

2

Visually
check
E
G
R

control

valve
for

damage
wrinkle
or
defonna

tion

3

Clean
the

seating
surface
of

E
G
R
control
valve
with
a
brush

and

compressed
air

and
remove

foreign

matter
from
around
the
valve
and

port