TM-9-2910-226-34
PUMP, FUEL, METERING AND DISTRIBUTING, ASSEMBLY
TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT, MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS
JUNE 1974
TM-9-2910-226-34 - Page 152 of 208
TM 9-2910-226-34
supply filters. Then if pressure is still low, replace
the over-flow valve. Fuel flow should be in ac-
cordance with Table 3-4 or 3-5, depending on pump
used. If reading in the burette (F, fig. 3-162) is not
within specifications, push in the fuel dumping lever
(E) to clear the burettes, and repeat test. If reading
is not within specifications, push in fuel dumping
lever to clear burettes. Fuel flow adjustment is made
by adjusting high speed adjustment screw (fig. 3-
173). Loosen the hex nut and turn the screw clock-
wise to decrease, or counterclockwise to increase the
fuel delivery. Make adjustments and repeat test
until specified fuel flow is attained. Tighten hex nut
to lock setting of the high-speed adjustment screw
Figure 3-173. Idle and High speed adjustment.
Table 3-10. Fuel Supply Pump Pressure (To Hydraulic Head)
Speed [rpm]
Pressure [psi]
2600-3100
60-80
1200
40-55
700
30-40
150
7 (min. )
(3) Adjust speed to 2600 rpm and check fuel
pressure on gage (A, fig. 3-162) at compensator
inlet. Fuel pressure should be 60-80 psi. Adjust stop
plate guide screw (fig. 3-174) on code C, D, and E
pumps, or (fig. 3-172) on code G pumps, to obtain
fuel flow per Table 3-4 or 3-5.
NOTE
Turn stop plate adjusting nut clockwise to
decrease fuel and counterclockwise to in-
crease fuel, as viewed at the governor end of
the pump. If fuel flow limit can not be ob-
tained by adjusting the stop plate, it will be
necessary to inspect the fuel control rod
linkage (para 3-25). Replace defective parts,
and repeat the tests to obtain specified fuel
flow. Check governor spring and spacers
(fig. 3-142, 3-143, 3-144, and 3-145).
F’igure 3-174. Adjusting stop plate guide screw and stop plate
for desired fuel delivery (code C, D, and E pumps).
(4) Increase pump speed to 2940 rpm and check
fuel flow. Flow should be 5 cc or less. If reading of 5
cc or less is not obtained, it will be necessary to stop
the test and check the high speed (inner) governor
spring spacer(s). See Table 3-11 for proper spacer
dimensions (refer to para 3-43). Check for use of the
correct spring (fig. 3-143). Check control unit for pin
wear (para 3-44).
NOTE
Adding spacers to the governor spring will
increase
fuel delivery,
and decreasing
spacers will decrease fuel delivery. Repeat
2940 rpm fuel flow check, and add or remove
spacers to obtain a fuel flow of 5 cc
maximum.
(5) Adjust speed to 1400 rpm and check fuel
pressure on gage (A, fig. 3-162) at compensator
inlet. Fuel pressure should be 40-55 psi. Check fuel
flow per Tables 3-5 or 3-4 respectively. (This is a
reference point only,) No adjustment is required on C
and D pumps. Adjust setscrew (droop screw) (J, fig.
3-67) on code E pumps. Turn screw clockwise to
decrease fuel delivery,
and counterclockwise to
increase fuel delivery. (Code C and D pumps do not
have a droop screw.)
(6) If fuel flow cannot be adjusted to these
limits, check engagement of compensator stop plate
and linkage on code C, D, and E pumps and angular
position of smoke limit torque cam on all pumps
(table 3-8). (Refer to figure 4-73.) Raising the cam to
a greater angle will increase fuel flow and decreasing
the cam angle will decrease the flow. Recheck fuel
flow.
(7) Reduce speed to 700 rpm and check fuel
pressure on gage (A, fig. 3-162) at compensator inlet
(code C, D, and E pumps) or head inlet (code G
3-106
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