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PART 1-1
-
ENGINES
Al
35
8 -1
FIG.
9-Cooli"9 Syslem
EJ
ENGINE TROUBLE DIAGNOSIS
Engine performance
complai nts
usually
fall under
onc
of
the basic
he
adi
ng
s
li
s
ted in the "Engine
Trouble
Diagnosis
Guide,"
When
a
particular trouble
can
not be traced
to
a
definite
cause by
a simple
check,
the possible
items
th at could be
at
fault
are
listed
in the order of
their
probab
le
occurrence,
Therefore, in
most
cases,
the
items
should be
checked
in the order
listed.
For
ex-
ample,
under Poor
Acceleration,
the
ENGINE TROUBLE DIAGNOSIS GUIDE
ENGINE WILL NOT
CRANK
ENGINE CRANKS
NORMALLY,
BUT WILL
NOT START
The
cause
of
this
trouble is usually
in
the starting syste
m (Part 10·2).
If
the
startin
g
system
is not at
fault,
check for
a
hydrostatic lock
or a
seized
engine
as follows:
Remove
the
spark plugs, then at-
tempt to
crank the
engine
with
the
Check
th
e
fuel
supply.
If
there is
sufficient
fuel in
the tank, the cause
of
the
trouble
probably
lies
in
either
the ignition Or the fuel
system.
To determine
which system
is at
fault, perform
the
following test:
Disconnect
a
spark plug
wire.
Check
the spark intensity
at
the end
of
the
wire
by installing
a
terminal
adapter in the terminal
of
the wire to
be
checked.
Hold
the
adapter ap-
proximately o/to
inch from the exhaust
manifold
and
crank the engine.
IF THERE IS NO SPARK OR
A WEAK SPARK AT THE
SPARK
PLUGS:
The
ca use
of the trouble is
in
the
ignition system.
To determine
if
the
ca use
of
the
trouble
is
in the
primary
or
the
sec-
ondary circuit,
remove
the
coil high
1-5
As the coolant enters the block. it
travels
through cored passages to cool
the
entire
length
of each cylinder
wall.
Upon
reac
hing the
rear of
the
cylin-
der block, the coolant is directed up-
ward
into the
cylinder
head where it
cools
the combustion chambers,
valves, and valve seats
on
its return
to the
front of
the
engine.
At thi
s
point,
the
coolant flows into
the coolant
outlet
connection,
past
the thermostat
if
it is open,
and
into
the top
of the
radiator.
If
the thermo-
stat
is
closed, a small
portion of the
coola
nt
is
ret
urned to
the
water pump
for
recirculatio
n.
The
entire system
is
pressurized to 13-1
5
psi.
ignition system
is
listed
as a
probable
cause of
th
e
troub
le.
All
the
ignition
system
items
that
affect acceleration
are
listed.
These
items
should all
be
checked before proceeding to the next
probable
cause.
starter.
If the engine
cranks.
it indi-
cates
that
water is
leaki
ng into the
cylinders.
Remove
the
cylinder
head
and
inspect the
gasket
and/
or
head
for cracks. Examine
the cylinder
block for
cracks.
tension
lead
from
the
top of the dis-
tributor and hold it
approxi
mately
~o
inch
from
the
cylinder
head.
With the
ignition
on, crank
the
engine
and
check
for
a
spark.
If the spark
at
the
coil
high tension
lead
is
good,
the
cause of
the
trouble
is probably in the
distributor
cap
or rotor.
If there
is
no
spark or a weak
spark
at
the
coil
high
tension
lead, the
cause of
the trouble
is
probably in
the primary
circuit, coil
to distributor
high te nsion
lead,
or
the
coil.
IF THERE IS A GOOD SPARK
AT THE SPARK PLUGS:
Check
the spark
plugs.
If
the
spark
plugs
are
not
at
fault,
check
the
following
items:
CHOKE
C
heck the
choke linkage
for bind-
ing
or
da mage.
Make
certain
the
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