MA
INTENANCE AND ADJUSTMENT
(3) Injection timing adjustment
70
(a) Pr
e-s
troke adjustment
"Pre·strokc"
refeIs
to
the
upward
movement of
the plunger (and hence
of
the tappet) and ;,
m
eas
ured
as
th
e
dis
tan<:
e
the
tappet
trlJve
ls
from
i
ts
lo
we
st pOsi
tio
n until the reed hole (in the
barrel) becomes
closed by the plunger.
Loosen
the
nozzle
holder
o\
'ernow
valve
; m
ove
the selector lever of the tester
to
"i
nje
ction"
pO
~Lt
io
n
;
a
nd
s
tart
ru
nning
th
e
high
-pre
ss
ure
p
um
p of the tester by engaging I
he
dutch
;
""d
,
with
the
tappe
t
cle.ar
a
nce
m
easu
rin
g devite
(95904-02100) secure
ly
installed, tllrn the cam·
shaft to bring N
o_
1 plunger
to
bo
llo
m dead
center (lowest) position.
From
this
po
sit
ion
of
c
amshaft
,
ro
ta
te
it
gently
in
nannal
dir
ection
to
raise
th.
e
tappe
t
(and
hen
ce
the plunger
)_
In
the
meant~
'Tle
,
fuel
will
be overflowing. Stop wming the camsha
ft
just
wh
en the fuel
ce
ases
to
o\'erflow I and r
ead
the
distance trave
rsed
by the tappet from Its
lo
west
position.
Mea
sur
in
g
pr
e-
stroke
Adjusting
pre-stroke
Unit; mm
(i
n.)
It@m
St
an
dard
Plunger pre.,troke
1.95 - 2.0
(0_0
77
-
0_019
)
If
the
reading
is
not
witltin t
he
$tandard
range,
adjust the
pr
e·stroke by repositioning the tappet
adj
ust
in
g boll v
ert
ic
ally
with tile tappet
wr
e
nc
h,
Tu
rni
ng
this bolt by about a half
roU
t
io
n vari
es
the pre·stroke
by
abou' 0.5 mm (0.020 in.).
Afte
r
making
[his
adjus
tment,
be
SUrf!
to
ha
...
c
the lock nut tightened f
ully_
Check and
ad
ju
st the oth
er
plungers
fO
I the
prc
3cr
ibcd
prc
o
3t
l"ok
c
by
rcp
ca
tinlj t
he
fo
tce;olht(
pJOce
dure.
(b) Checking and adjusti
ng
the angul
ar
position
of
the
beginning
of
in
je
ction
The end
of
pre.stroke corresponds
to
the begin·
ning
of
injection; the plunger begin. to pres-
s
urize
the
f
uel
in
.
the
barre.l
whe
n
it
hilS
just
closed the reed hole.
Take the position or
No
_ I plunger at it, begin-
ning
of
injection
as
the reference
angular
position (0
deg_),
and check the angular position
at
whic
h each of the
Ie"
of
tlte plunge. begins
to
inject.
Make
s.ure
that
the
beginning of
injec
ti
on
comes
w~th.in
the
J
deg.
tole
ran
ce
of
the
an
gu[,
u
value
pr
e
scr
ibed :
Itam
Standard beginning
of
In
iection
Angular
No.1
NO.2
No_
3
No.4
spacing of
89'30'
11
9'30'
269
'30
'
1.1
injec
tion
O·
timing
"",()Oo30'
-180'30'
"'210' 30'
--
--
Incre
ase
or decre
ase
the pre·stroke to bring
Ihe
beginning
of
injection,
as
necessary. into
Ihe
tolerance allowed. Turning the tappet adjusting
Check
ing
in
te
rva
l between infectio
ns
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