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