TM 5-2420-230-24-2
roubleshooting Symptoms Charts
B3.9 and B5.9 Series Engines
Page TS-58
Section TS - Troubleshooting Symptoms
Engine Will Not Reach High Idle
This is symptom tree T080-005.
Cause
Correction
Compare the tachometer reading with a
handheld tachometer or an electronic service
Tachometer is not calibrated or is malfunction-
.......
tool reading. Calibrate or replace the tachom-
ing
eter as necessary. Refer to the OEM service
manual.
OK
E
Check for added loading from malfunctioning
accessories or other engine-driven units,
ngine under excessive load
.......
brakes dragging, or other changes in vehicle
loading. Disengage engine-driven units.
OK
A
Check and repair fan shroud, viscous fan as
irflow to the radiator restricted
.......
required. Refer to OEM service manual.
OK
E
Make sure the throttle linkage is not
misadjusted or damaged. Adjust and repair as
ngine will not reach full throttle
.......
necessary. Check the fuel lever for stop-to-stop
travel. Refer to Procedure 005-036.
OK
F
uel shutoff lever (mechanical) partially
Check for correct solenoid operation. Refer to
.......
engaged
Procedure 005-043.
OK
P
Verify by operating the engine from a tempo-
rary supply of No. 2 diesel fuel. Check fuel
oor fuel quality or wrong fuel grade
.......
specifications for proper fuel grade. Refer to
the Operation and Maintenance Manual, B
Series Engines, Bulletin No. 3810205.
OK
F
Check the flow through the fuel filter. Replace
the fuel filter if necessary. Refer to Procedure
uel filter or fuel inlet restriction
.......
006-015. Clean all prefilters and screens.
Check the fuel suction line for restriction.
OK
F
uel pump return overflow valve is malfunction-
Inspect the return overflow valve. Replace if
.......
ing
necessary. Refer to Procedure 006-044.
OK
T
(Continued)
L-642
