band,
while
holding
the
barrel
horizontal:
then
angle up the barrel slowly
by
about 60° . This
should
cause
the
pitmgtr
to
slide
in
all
the
way
by
Its
own
weight to evidence a proper
fi
t.
If
the
plunger
goes
inward
in
a f
ree-falling
manner
or
become
s stuck
on
the
way,
then
the
pump
i
ng
element
must
be
replace
d.
!lSI(
~
..
//
f
Ch
ec
kill9 pumping element for fit
(2) Delivery vah'e
test
Each
delivery
valve
mus
t
be
lested
for
seating
lightness.
Before
testing
it,
inspect
its piston,
valye
seat
and
other
parts
for
wear
.
If
any
part
is
exces-
s
ively
worn
or
if
the
:seating
contact
is
defective.
replace
lhl;
vah'e
piston
and
seat
as
a
uni
t.
Set
up
the
assembled
injection
pump
on
the
test
stand
!
with
a lest
pressure
gauge
installtd
on
the
delivery
v
alve
holde.,
as
in
the
fuel·tightness
test
outlined above. [The gauge should
be
capable
of
indicating up to
300
kg/cm' (4266 psi)
Or
400
kg/cm'
(5688 psi)[ . Run the
pump
until
,h.
pressure gauge read, s
li
ghtly above 150 kg/em'
(2133 psi).
With.
stop
watch in the hond, pull the
control
rack
to
non
.injection
pO'sit~on
and, at the
same
time. stilIl clocking
the
tune
required
by
the
fuel pre
ss
ure (ahead
of
the delivery
v'
lv
e)
to fall
(due to leakage past the
se.ted
valve
) 10 kg/em'
(142 psi).
If
Ihis duration is
not
less
lhan 5 sec·
onds,
then
the
delivery
val\'e
is
satisfactorily
tight.
Item
Service
limi t
Seating lightness of
delivery
valve
in
terms
of
duration
for
5
se
c
onds,
m
inimum
a
drop
of
10 kg/ern' (142 psi)
from I
SO
kg/em'
(21
33 p
si
)
When
the
injection
pump
is
in
disa5&embled
state,
check the
fit
of the deb very valve piston
in
the
bore
by
holding
Ih
t!
valve
wi
th
fingers
as
shown
.
Finl
, let
down
thl!
valve
all
the
way
into
the
bore
,
MAINTENANCE AND ADJUSTMENT
and
give
thumb
pressure to the bore. This should
r
aise
the
val'ole
a
titde
an
d
releas
e of
thumb
pressur
e
shouJd
aUow
it
to
s
eule
in
to
seated
condition; if
the
val
ve re
mains
scaled
without
res.p
o
ndin
g
to
the
t
hum
b pressure. its fit in the
bore
is
IOO
loose.
.
~
.. ' .
",-'
,or. . r
.
~.
'
.'
Jaell
Chec
ki
ng
del
i
very
valve
for
fit
(3) Wear
of
control rack
ond
pinioll'
The
c
ontrol
r
ack
must
be
replaced
if
It
js
found
dis.torted
or
bent
Or i!s
rack
teeth
are
exccssivety
worn. After
assembling
the
injection
pump
,
cnet:k
each
pinion
ror
backlash
,
and
repi.:lce
pi.nions
fo
u
nd
to exce
ed
the
service
limit
on
backlash.
Unit:
mm
(in.l
I Standard
Servi~
Item
Ilm;t
~.lS
0.25
Pinion.to
.r
a~k
backlash
(0
.
0059)
(0
.0098)
Using a s
pring
scale,
check
rhe
force
necessary
to
set
the
control
rack
in
sHding
motion.
Repair
or
replace
the:
control
rack
ff
it offers a
res
i
stance
requir
ing
a
greater
force
to
overcome
than
J
SO
gr.uns
(5
.
25
oz).
Checking
!Sliding
resi5tance
of
control
rack
67
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