TM-5-3805-254-14-P-2
TRUCK, DUMP, 20 TON, 6X4, ON-OFF HIGHWAY 71,000 GVW, IHC MODEL F-5070 (CCE)
TECHNICAL MANUAL; OPERATOR’S, ORGANIZATIONAL, DIRECT SUPPORT, GENERAL SUPPORT AND DEPT MAINTENANCE MANUAL (INCLUDING REPAIR PARTS INFORMATION AND SUPPLEMENTAL MAINTENANCE INSTRUCTIONS)
JUNE 1980
TM-5-3805-254-14-P-2 - Page 537 of 894
TRUCK SERVICE MANUAL
FUEL SYSTEM
Table 5-1-8: Calibration Recheck Specifications
Check
Recheck A-One
Recheck B-Tested
test stand to
and readjusted on
another
engine to fuel
pump test stand
Governor Cut-Off
-O to +10 RPM
Rated speed to
RPM
from published
50 RPM above
values
rated speed
Manifold pressure
+10%or+ 1 PSI+ 30% from
at idle speed
which ever is
published value
larger
Manifold pressure
+- 2 PSI from
Same variance as
at rated speed
published value
on engine mani-
fold pressure
tolerance plus
an additional
+2 PSI
Throttle Leakage
+ 15cc If 100 cc/min
or less
+ 15cc to -35cc/min
if over 100 cc/
min.
Idle Setting
-2 to + 4 PSI
First manifold
+- 1 PSI from published values Rated
pressure check
speed manifold pressure must first be
point
to spec.
by adjusting flow valve.
Second manifold
A
If first check point is +1 PSI, sec-
pressure check
ond check point to be from pub-
point
lished min. spec to +1 PSI
above published max.
B
If first check point is -1 PSI, sec-
ond check point to be from pub-
lished max. spec to -1 PSI
below published min.
C
If first check point is within pub-
lished spec.
second check point
must be within published spec.
Manifold pressure
-+ 1 PSI from published value.
at Wt.
Assist
check point
Pump Specifications
1.
Governor Cutoff R.P.M.
The governor cutoff R.P.M.
is defined as the RPM where the
manifold pressure starts to decrease from the maximum
observed pressure as the speed is increased.
a.
When checking from one test stand to another, cutoff
speed can vary _ 10 RPM from the published cutoff RPM
(i.
.; 2520-2540 RPM cutoff speed, reflow can be 2510-
2550 RPM).
Suction vacuum must be set at 5 inch Hg.
b.
Recheck from engine test to test stand, cutoff speed
can be from rated speed to 50 RPM above rated speed (i.e.;
rated speed 2500 RPM, cutoff speed at reflow can be 2500-
2550 RPM).
Suction vacuum must be set at 5 inch Hg.
2.
Throttle Leakage
Throttle leakage is set with the throttle lever held firmly closed.
The pump is operated at rated speed and the fuel delivery is
measured for one minute.
Recheck from one test stand to another or from tested engine
to test stand can vary +15 cc from published value (I.e.; 35 cc
throttle leakage can be 20 to 50 cc at reflow), If leakage is 100
cc/min, or less.
When leakage is 100 cc/min. or over, It can
vary +15 cc to - 35 cc/min.
(I.e., 150 cc/min.
leakage can be
115 cc to 165 cc/min.
at reflow).
3.
Idle Speed Manifold Pressure
a.
Recheck from one test stand to another, manifold
pressure can vary _ 10% from specifications or + 1 PSI
whichever is larger, (i.e.; 20 PSI @ 500 RPM can be 18-22 PSI
at recheck or 3 PSI @ 500 RPM can be 2-4 PSI at recheck).
b.
Recheck after engine adjustment, manifold pressure
can vary + 30%/0 from specifications, (i.e., 20 PSI @ 500 RPM
can be 14-26 PSI at recheck).
4.
Manifold Pressure at Rated Speed
a.
Recheck from one test stand to another, manifold
pressure can vary + 2 PSI from published specifications, (i.e.,
126 PSI manifold pressure can be 124-128 PSI at reflow).
Suction vacuum must be set at 5 inch Hg.
b.
Recheck after engine adjustment; manifold pressure
can vary the same as the on engine fuel pressure tolerance
plus an additional + 2 PSI, (i.e.; if on engine pressure
specification is 114-126 PSI or 6 PSI the tolerance for the
manifold pressure at recheck is (+ 6) + (+ 2) = + 8 PSI. Then
126 PSI manifold pressure can be 118-134 PSI at reflow).
Suction restriction must be set at 5 inch Hg.
5.
Manifold Pressure Check Point
Recheck pump at rated speed and obtain exact manifold
pressure per calibration specification by adjusting the flow
control valve.
Suction restriction must be set at 5 inch Hg.
l.
First check point can vary ± 1 PSI from the published
specifications, (i.e.; 100-106 PSI @ 2000 RPM can be 99-107
PSI at reflow).
II.
Second check to be as follows:
a.
If pump checks + 1 PSI at first check point, it must be
at published
minimum
specifications
to
+
1 PSI above
published maximum specifications at second check point, (i.e.;
75-81 PSI @ 1500 RPM can be 75-82 at recheck).
b.
If pump checks - 1 PSI at first check point, it must be
published maximum to - 1 PSI below published minimum
532
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