1968 DATSUN 510 jump start

TROUBLESHOOTING
13

trouble

may
also
be
worn

bearings
Remove
the

alternator
and

repair

ENGINE

These

procedures
assume
the
starter
cranks

the

engme
over

normally
If
not
refer
to
Starter

section
m
this

chapter

1

Engme
won
t
start

Could
be

caused

by
the

IgOltlon
or
fuel

problems

First
determine
If

high
voltage
to

spark
plug

occurs
To
do
thiS
dISconnect
one
of
the

spark

plug
wires
Hold
the

exposed
wrre
termlOal
y
to

Y2
lOch
from

ground
any
metal
in

engine
com

partment
With
an
msulated
screwdriver
Crank

the

engme
over
If

sparks
do
not

Jump
to

ground

or
the

sparks
are

very
weak
the
trouble

may
be

10
the

IgnitIOn
system
See

Ignition
System
Trou

bleshootmg
to
further
check
If

sparks
occur

properly
the
trouble

may
be
10
the
fuel

system

See
Fuel

System
Troubleshootmg

2

Engme
misses

steadily

Remove
one

spark
plug
wrre
at
a
tune
and

ground
the
wrre
If

engme
mISs
increases
that

cyhnder
was
work

109
properly
Reconnect
the

wire
and
check
the
others
When
a
wire

IS
dIs

connected
and

engme
miss
remams
the
same

that

cylinder
IS
not

finng

Check

spark
as
descnbed
10

Step
1
If
no

spark

occurs
for
one

cyhnder
only
check
dlStnbutor

cap
wrre
and

spark
plug
If

spark
occurs

prop

erly
check

compressIOn
and
mtake
maOlfold

vacuum
to
ISolate
the
trouble

3

Engme
misses

erratlcally
at
all

speeds

Interrmttent
trouble
can
be
difficult
to
find
It

could
be
ill
the

Ignition
system
exhaust

system

or
fuel

system
Follow

troubleshooting
proce

dures
for
these

systems
carefully
to
isolate
the

trouble

4

Engme
misses

at
Idle

only

Trouble
could
exist

anywhere
ill

IgOltlon
system

Follow

Ignition
TroubleshootlOg
procedure
care

fully
Trouble
could
also
eXist
10
the
carburetor

Idle
crrcult
Check
Idle
mIXture

adjustment
and

check
for
restnctions
m
the
idle
crrcUlt

5

Engme
misses
at

high
speed
only

Problems
could
be
ill
the
fuel
or

IgOltlon
systems
heck
accelerator

pump
operation
fuel

pump

dehvery
fuel
hnes
etc
as
descnbed
under
Fuel

System
Troubleshootillg
Also
check

spark
plugs

and
wrres

6
Low

performance
at
all

speeds
poor

acceleratIOn

Trouble

usually
ill

IgOltlon
or
fuel

system
Check

each
With
the

appropnate
troubleshooting
pro

cedure

7
ExceSSive

fuel
consumptIOn

Could
be
caused

by
a

Wide

variety
of

seemmgly

unrelated
factors
Check
for
clutch

shppage

brake

drag
defective
wheel

beanngs
or

poor

front
end

alignment
Check

IgOltlOn
system
and

fuel

system

8
011

pressure
lamp
does
not

light
when

IgmtlOn

switch

IS
on

Check
the
alternator

warning
lamp
If
it
ISn
t
on

either

go
to

Step
1

Chargmg
System
Trouble

shootlOg
If

only
the
oil

pressure
lamp
IS
off

open

the

englOe
compartment
hd
and
locate
the
oil

pressure
sender
on
the
block
near
the
oil
filter

Make
sure
the
wrre
is
connected
to
the
sender

and

makmg
good
contact
Pull
the
wrre
off
and

ground
it
If
the

lamp
hghts
replace
the
sender

If
the

lamp
does
not

light
replace
the

lamp

9
011

pressure
lamp
lights
or

flickers
when

engme
IS

runmng

Indicates
low

or

complete
loss
of
oil

pressure

Stop
the

englOe
unmedmtely
coast
to
a

stop
With

the
clutch

dISengaged
Tlus

may

simply
be

caused

by
a
low
oil
level
or
an

overheatmg
en

glOe
Check
the
oil
level
and
fan
belt
tensIOn

Check
for
a
shorted
oil

pressure
sender
with
an

ohmmeter
or
a

contlOulty
tester
Remove
and

clean
the
oil

dipstick
and
check
oil
level
and

condition

RepleOlsh
or

replace
the
oil

as
re

qurred
Listen
for
unusual
nOISes

mdlcatmg
dam

aged
beanngs
etc
Do
not
re
start
the

engine

until

you
know

why
the

hght
went
on
and

are

sure
that
the

problem
has
been
corrected

IGNITION
SYSTEM

This

procedure
assumes
the

battery
IS
ill

good

enough
condition
to
crank
the

engme
at
a

normal
rate

14

CHAPTER
THREE

I
No

spark
to
one

plug

The

only

possible
causes
are
a
defective
dlStri

butor

cap
or

spark
plug
wrre
Examme
the
dis

tnbutor

cap
for
mOisture
drrt
or
carbon
track

ing
caused

by
flashover
cracks
etc

2
No

spark
to

any

plug

ThlS
could
mdicate
trouble
in
the

prImary
or

secondary
Circuits
Frrst

remove
the
coil
wire

from
the
center

post
of
the
dlStributor

Hold
the

Wire
end
about
1
1
mch
from

ground
With
an

msulated
screwdrIver

Crank
the

engme
H

sparks
are

produced
the
trouble
is
m
the
rotor

or
distributor

cap
Remove
the

cap
and
check

for
burns

mOisture
dirt
carbon

trackmg

cracks
etc
Check
the
rotor
for
excessive
burn

mg
pittmg
or
cracks

Replace
both
rr

necessary

H
the
cod
does
not

produce
any
spark
check

the

secondary
Wire
for

opens
H
the

wrre
is

good

turn
the

engme
over

so
the

breaker

pomts
are

open
Examme
the

points
for
excessIVe

gap

burmng

pittmg
and
looseness

Replace
and
ad

Just
rr

necessary
With
the

points
open
check

voltage
to

ground
at
the
cod
with
a
voltmeter
or

test

lamp
If

voltage
is

present
the
cOlllS

prob

ably
bad
Have
it
checked
or

substitute
a
known

good
one

If

voltage
is
not

present
check
wrre
connec

tions
to
cOll
and
distrIbutor

Temporanly
dIs

connect
the
Wire
from
the
distrIbutor

to
the
cOll

and
measure
from
the
coli

to

ground
If

voltage

is

present
the
distnbutor

lS
shorted

Examme

the
breaker

pomts
and

connecting
WIres
care

fully
If

voltage
is
still
not

present
check
the

other
coli
termmal
for

ground
Voltage
at
thiS

termmal
but
not
at
the
other
mdicates
a
defecnve

cOll
No

voltage
at
tlus

termmal
mdicates
an

open
Wire
between
the

termmal
and
the

battery

3
Weak

spark

If
the

spark
lS
so
small
it

cannot

Jump
from
the

wrre
to

ground
check

battery
condinon
Other

causes

are
bad
breaker

points
condenser
m

correct
breaker

pomt
gap
dirty
or
loose
con

necnons
m
the

pnmary
crrcuit
or

dirty
or
burned

rotor
or
distnbutor
Also
check

for
worn
dis

tnbutor
cam
lobes

4

Mlssmg

ThiS
is

usually
caused

by
fouled
or

damaged

plugs

plugs
of
the

wrong
heat

range
or
mcorrect
plug
gap
Clean
and

regap
the

spark
plugs
flus

trouble
can
also
be

caused

by
weak

spark
see

symptom
3
or
mcorrect

igmnon
tlIDing

5

Spark
polarity

Less

voltage
is

requrred
to
cause
electron
flow

from

a

relatively
hot
electrode
to
a
cooler
elec

trode

Smce
the
center
electrode
is
hottest
this

electrode
should
be

negative
Electron
flow
lS

then
from
the
center
electrode
to
the
outer
elec

trode
From
20
to
40

percent
more

voltage
is

requrred
to
cause
electron
flow
from

the
outside

electrode
to
the
hotter

center
electrode
This

occurs
when
the

spark

voltage
is

positive
The

cOll
wrres
must
be

connected

correctly

FUEL
SYSTEM

Fuel

system
troubles
must
be
iSolated

at
the

carburetor
fuel

pump
or
fuellrnes
These

pro

cedures
assume
that
the

igmtlon
system
has

been

checked
and

properly
adjusted

I

Engme
Will

not
start

Frrst
detenmne
that
fuellS

reachIng
the
carbu

retor
Remove
the

au
cleaner
look
into
the

carburetor
throat

and

depress
the
accelerator

several
tlIDes

There
should
be
a
stream
of
fuel

from
the

discharge
tube
each
time
the
accelerator

lS

depressed
If
not
the
fuel

pump
lS
not
dehver

mg
fuel
to
the
carburetor
or
the
float

system
m

the
carburetor
lS
not

workmg
Make

certam

there
is
fuel
m
the
fuel
tank
Check
the

automatic

choke
rr
so

equipped
to
make

certain
it
is
not

stuck
If

necessary
rebudd

the
fuel

pump
or

overhaul
the
carburetor

whichever
lS
determmed

to
be

faulty

2

Engme
runs

at

fast
Idle

Usually
thiS
is
caused

by
misadJustment
of
the

carburetor
idle

setting
Readjust
as

required

3

Rough
Idle

or

engme
miss
with

frequent

stallmg

Check
idle
miXture

and
idle

speed
adjustments

Inspect
the

overall
conchtlOn
of
the
carburetor

for

foreign
material
and
clean

or
overhaul

as

required

4

Engme
diesels

contmues
to
run

after

engme
IS
turned

off

Check
idle
IDlXture

and
idle

speed
adjustments

ENGINE
ELECI
RlCAL
SYSTEM
97

No
Load
Lock

Torque
Test

1
Connect
the
starter
motor
in
series
with

a

12
volt

battery
and
antmeter
as
shown
in

Figure

19
The
antmeter
should
be

capable
of

mdIcatIng

1
000

amps

@
Switch

Voltmeter
Ammeter

2
Use

torque
testlng
equipment
to
determine

the

torque
the
motor

develops

3
Connect
a
voltmeter
and
a
vanable
resistor

WhICh
IS
used
to

regulate
the

voltage
Into
the

circwt

4
Close
the
sWitch

and

regulate
the

voltage
as

reqUIred
Figure
20

proVIdes

power
voltage

amperage
and

torque
mformatIon

that
1f
fol

lowed
will
mdIcate
the
condItion
of
the
starter

motor

Power
kw

Voltage
v

@

Test

Diagnosis

1
Low

speed
with

high
current
draw

might
re

sult
from

tIght
dirty
or
worn

bearings
bent

armatlIre
shaft
loose
field
call
or
a
shorted

armatlIre

2
Fatlure
to

operate
With

htgh
current
draw

may
result
from
a

gromlded
or

open
field
coil
a
defectIve
armature
coll
or
a
burned

out
com

mutator
bar

3
Low

torque
low
current
draw
and

low

speed

would
be
caused

by
hIgh
Internal
reSIStance
due

to
loose
connectIons

dirty
commutator
defec

tIve
leads
and

a
burned
out
commutator
bar

4

HIgh
speed
With
low

torque
would
be
caused

by
a

grounded
field
coll

Magnetic
Switch

Assembly
Test

H
the
above
tests
are

satIsfactory
check
the

magnetIc
SWitch

assembly
as
follows

1
Connect

Jumper
cables
between
the

negative

battery
tennmal
and
the
starter
motor
M
term

inal

as
shown
In

Figure
21
Also
connect
the

positIve
battery
terminal
to
the
S
terminal
and

place
a
SWitch
m
senes
in
the
CIrCuit

@
Ignition
switch

9

I

i
j

Battery
Starter
motor

rr

2
Close
the
SWitch
and
measure
the

dimension

given
m

Figure
22
The
dimensIon
should
be
as

specIfied

o
0591m

15mm