'Jeep'
UNIVERSAL
and
'Jeep'
DISPATCHER
c
ENGINE TUNE-UP
Contents
SUBJECT
PAR.
Air
Cleaner.
. . . . . . . . . . . .
..........
C-12
Battery.
. . . . . . . . . . . . . . . . . . . .
...........
C-2
Carburetor....
. . . . . . . . . . . . . .
.........
C-16
Compression
.............................
C-7
Crankcase
Ventilation
.....................
C-5
Cylinder
Head
...........................
C-4
Distributor
..............................
C-9
Fuel
Pump
...............................
C-14
C-1.
GENERAL
An
engine
tune-up
should
be
performed
each
6,000
miles [9.600 km.],
or
at
the
end
of
each
250
hours
of
off-the-road
use,
to
restore
performance
and
power
lost
through
wear
and
deterioration
resulting
from
vehicle use.
The
tune-up
should
follow
the
sequence
given
below.
Correction
of
items
affecting
the
fuel
system
should
not
be
attempted
until
all
items
affecting
compression
and
ignition
have
been
satisfactorily
checked
and
any
problems
corrected.
C-2
Clean
and
Check
Battery
Inspect
battery
and
cables.
If
the
battery
is
not
satisfactory,
install
a
fully-charged
battery
to
allow
completion
of
the
tune-up.
a.
Check
the
specific
gravity
of
the
electrolyte
in
each
cell
of
the
battery.
A
hydrometer
reading
of
1.260
indicates
that
the
battery
is
fully
charged.
If
the
reading
is 1.225
or
below,
the
battery
needs
recharging.
If
one
or
more
cells is
25
"points"
(.025)
or
more
lower
than
the
other
cells,
this
in-
dicates
that
the
cell
is
shorted,
the
cell is
about
to
fail,
or
there
is
a
crack
in
the
battery
partition
in
the
case.
Unless
the
battery
is
repaired
or
replaced,
battery
trouble
will
soon
be
experienced.
b.
Check
the
electrolyte
level
in
each
cell,
add
distilled
water
to
maintain
the
solution
%"
[9.5
mm.]
above
the
plates.
Avoid
overfilling.
Replace
the
filler
caps
and
tighten
securely.
It
is
important
to
keep
the
electrolyte
level
above
the
plates
at
all
times
because
plates
that
are
exposed
for
any
length
of
time
will
be
seriously
damaged.
c.
Check
the
wing
nuts
on
the
hold-down
frame
for
tightness.
Tighten
them
only
with
finger
pres-
sure,
never
with
pliers
or
a
wrench.
Excessive
pressure
could
damage
the
battery
case.
d.
Clean
the
battery
terminals
and
cable
con-
nectors.
Prepa,re a
strong
solution
of
baking
soda
and
water
anal
brush
it
around
the
terminals
to
remove
any
corrosion
that
is
present.
The
cell
caps
must
be
tight
and
their
vents
sealed
to
prevent
cleaning
solution
entering
the
cells.
After
cleaning,
coat
the
terminals
with
heavy
grease.
e.
Inspect
the
battery
cables
and
replace
if
badly
SUBJECT
PAR.
Fuel
Supply
..............................
C-13
Heat
Control
Valve
.......................
C-6
Ignition
............................
C-10, C-11
Service
Diagnosis
. . . . . . . . . . . . . . . . . . . . . . . . . C -19
Spark
Plugs
..............................
C-3
Tune-Up
Specifications
....................
C-20
Vacuum
.................................
C-15
Valve
Adjustment
........................
C-8
corroded
or
frayed.
Check
tightness
of
terminal
screws
to
ensure
good
electrical
connections.
Check
the
tightness
of
the
negative
ground
cable
co
1-
nection
at
the
frame
to
ensure
a good
ground
connection.
f.
Load
test
the
battery.
Connect
a
voltmeter
across
the
battery.
Run
the
starting
motor
for
15 seconds.
If
the
voltage
does
not
drop
below 5
volts
on
a
6-volt
battery,
or
10
volts
on
a
12-volt
battery,
the
battery
is
satisfactory.
If
the
voltage
falls
below
the
figures given,
yet
the
specific
gravity
is
above
1.225,
the
condition
of
the
battery
is
questionable.
g.
Be
sure
the
engine
ground
strap
connection,
Fig.
20,
is
tight
at
both
connections.
If
these
connections
are
loose
or
dirty,
hard
starting
or
failure
to
start
may
result.
FIG.
20-ENGINE
GROUND
STRAP
C-3.
Clean
and
Adjust
Spark
Plugs
Clean,
inspect,
and
gap
spark
plugs.
Do
not
install
spark
plugs
until
completion
of
compression
tests.
a.
Using
a
spark
plug
wrench,
loosen
each
spark
plug
one
or
two
turns
to
break
loose
any
carbon
deposits
on
the
plug
base.
b.
Blow
out
all
carbon
and
dirt
from
each
spark
19
To Next Page
Loading...
