TM 9-6115-604-34
NAVFAC P-8-633-34
(5)
Close the throttle leakage valve (8. Figure 6-17).
(6)
Leave the locking pliers and universal spring positioned as in step (1), above, for use in setting the idle
speed in step e, below.
e.
Idle Speed.
(1)
Ensure that the locking pliers and universal spring are positioned as in step d (1), above, so that the throttle
shaft (45, Figure 6-11) is held fully dosed (rotated fully clockwise).
(2)
Close the fuel flow control valve (5, Figure 6-17 ), and open the idle orifice valve (10).
(3)
Ensure that the control end (51) on the throttle shaft (45) is held against the adjusting screw (55), located
towards the rear of the fuel pump housing (66), by the universal spring installed in step d (1), above.
(4)
Adjust the fuel pump speed to 600 rpm.
(5)
Remove the plug (7, Figure 6-11) at the rear of the lower spring pack cover (5). Using the idle speed
adjusting tool 3375981, adjust the idle adjust screw (13) until the leakage flowmeter (13, Figure 6-17)
indicates the flow of 310 i± 5 cc/min. at the established fuel pump speed of 600 rpm.
f.
Throttle Travel and Calibration Pressure.
(1)
Position the locking pliers and universal spring as in step b (9), above, so that the throttle shaft (45, Figure
6-11) is held fully open (rotated fully counter clockwise).
NOTE
During the following procedure, do not change the position of the adjusting screw (55, Figure
6-11), located towards the rear of the fuel pump housing (66), from its setting established in
step d, above.
(2)
Using a protractor, adjust the adjusting screw (55, Figure 6-11), located towards the front of the fuel pump
housing (66), so that the throttle shaft (45) travel (rotation) between the adjusting screws (55) is 27 to 29
degrees. This will ensure full fuel flow through the throttle shaft (45) metering passage.
(3)
Lock the adjusting screw (55), located towards the front of the fuel pump housing (66), by tightening the
hexagonal nut (54).
(4)
Ensure that the throttle shaft (45) is held in the fully open position (rotated fully counter clockwise). Close
the idle orifice valve (10, Figure 6-17) and throttle leakage valve (8), and open the fuel flow control valve
(5).
(5)
Adjust the fuel pump speed to 1800 rpm.
(6)
Check the torque required to turn the fuel adjusting screw (48, Figure 6-11) is at least 1.5 pound-inches
(0.169 newton-meters). Replace the fuel adjusting screw (48) if torque required is less than this.
(7)
Adjust the fuel flow control valve (5, Figure 6-17) until the main flowmeter (15) indicates 1275 lbs/hr (575
kg/hr), and adjust the suction valve (4, Figure 6-16) until the vacuum gage (7, Figure 6-17) indicates 7
inches (178 mm) Hg, or as close as possible.
(8)
Using the fuel adjusting screw (48, Figure 6-11), adjust the fuel pressure as indicated by fuel pump
pressure gage (18, Figure 6-1 7), to 185 psi (1276 kPa). Recheck in accordance with steps (4) through (7),
above.
(9)
Leave the locking pliers and universal spring positioned as in step (1), above, for use in checking the check
point pressure in step g, below.
g.
Check Point Pressure.
(1)
Ensure that the locking pliers and universal spring remain positioned as in step f, above, so that the throttle
shaft (45, Figure 6-11) is held fully open (rotated fully counter clockwise).
(2)
Reduce the fuel pump speed to 1500 rpm.
(3)
Adjust the fuel flow control valve (5, Figure 6-17) until the main flowmeter (15) indicates 1080 lbs/hr, (486
kg/hr), and check the fuel pressure as indicated by the fuel pump pressure gage (18). Fuel pressure must
be 137 to 143 psi (945 to 986 kPa).
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