TM 5-6115-400-35
(10) Adjust the graduated wheel on the test
stand so that the zero mark on its rim
lines up with the pointer.
(11) Recheck the number one pump element
for port closing to make sure that the fuel
stops flowing from the delivery valve
holder when the pointer lines up with the
zero mark on the test stand wheel. THIS
IS IMPORTANT.
(12) Having thus determined the port closing
position for plunger number 1, remove the
delivery valve holder and re-install the
delivery valve and spring previously
removed. Make sure these parts are
clean. Replace the delivery valve holder
and tighten it firmly, but not excessively.
(13) Now proceed to the next pump element in
the firing order which is 1-5-3-6-2-4.
Determine port closing of the next pump
element in the same manner as outlined
for plunger number one, except that it
should occur 60 degrees later. Proceed
until all six pump elements are timed at
60 degree intervals in firing order.
(14) As an example, when checking the
number five plunger, the fuel should stop
Figure 19. Fuel injection pump timing marks for
flowing when the graduated wheel on the
internal timing
test stand indicates 300 degrees. Add or
remove spacers as necessary.
Also
(7) Replace the delivery valve holder.
check each pumping element for proper
Manually turn the drive until number one
clearance between plunger and delivery
(1) plunger of the pump is in its lowest
valve body at top-dead-center.
position. The spill port now being open,
(15) Only one spacer is used between the
fuel will flow through the delivery valve
tappet and the tappet knob. Spacers are
holder.
furnished in sizes of 0.050, 0.054, 0.058,
0.062 and 0.066 inch.
Note. The pump must be rotated
counterclockwise for each timing
Note.
0.004 inch is about 1/2
operation to obtain accurate readings.
degree on the graduated wheel of the
Back-lash in test stand and pump parts
test stand.
may otherwise cause erroneous
settings,
far
beyond
specified
(16) Only 1/2 degree tolerance is allowed on
tolerances.
the fuel settings. If any deviation from
these figures is observed, the plunger
(8) Turn the pump counter-clockwise, through
must be adjusted.
the port opening position, just to the point
where the fuel stops flowing.
This
h. Calibrating the Fuel Injection Pump. Engine
indicates the port closing position.
performance depends to a great extent upon the
(9) The timing mark on the drive flywheel
accuracy with which the injection pump is calibrated.
should now coincide with the timing mark
pointer. Eliminate the old mark by filing,
if necessary, and establish a new one.
46
