Timing:
Pump
timing
procedures
determine
the
correct
thickness
of
shims
between
pump
and
engine
so
port
closing
occurs
at 17
0
BTC.
The
most
accurate
method
of injection
pump
timing is
with
a
depth
micrometer
(Method 1).
However,
if a
depth
micrometer
isn't
available,
time
it by Flowing the
Pump
(Method 2).
NOTE: Injection pump must be timed on the compres-
sion stroke, not the exhaust stroke.
METHOD
1.
DEPTH
MICROMETER
METHOD
1.
Install
pump
tappet
in its
recess
and
position
fly-
wheel
on the
port
closing
mark
(PC) of the
com-
pression
stroke.
2.
Using
a
depth
micrometer,
measure
the
distance
from the
pump
mounting
pad on the
crankcase
to
the
tappet
center.
See
Figure
20.
3.
Subtract
from the
port
closing
dimension
of the
pump
(1.670-inch)
the
depth
obtained
in
step
2. Hie
result
is the
thickness
of
shims
necessary
to
cor-
rectly
time
the
pump.
NOTE: Thickness ol shims may vary irom 0.006-
inch to 0.052-inch. If it does not fall within these
limits, check camshaft and tappet for excess wear
. or improper assembly.
4.
Select
the
correct
shims
for the
required
thickness.
5. Install the
pump.
DEPTH
CROMETER
METHOD 2. FLOWING THE PUMP
"1.'
Install
pump
with
0.006-inch
shims
between
pump
and pad.
2.
Loosen
the
delivery
valve
holder
to
relieve
pres-
sure
on
spring.
See
Figure
21.
3.
Rotate
the flywheel to
about
15°
before
the
port
closing
(PC)
point.
Blow in the
pump
inlet and
rotate
the flywheel slowly
clockwise
until air
stops
coming
out of the
pump
outlet.
This
is the
port
closing
point.
4.
Measure
the
distance
from the
point
where
port
closing
occurs
to the PC
mark
on the flywheel.
Find the
thickness
of
shims
to be
added
from the
table
that
follows.
5. Install the
pump.
INSTALLATION:
Prior
to
mounting
the injection
pump
to the
cylinder
block
follow
steps
1
through
3.
•DELIVERY
.VALVE
SPRING
INJECTION
PUMP
^
TRANSFER
PUMP
\ PRIMING
LEVER
FIGURE 20. DEPTH MICROMETER
FIGURE
21.
LOOSENING
DELIVERY
VALVE
HOLDER
21
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