TM 5-2420-230-24-2
3.9 and B5.9 Series Engines
Troubleshooting Symptoms Charts
Section TS - Troubleshooting Symptoms
Page TS-43
Engine Power Output Low (Continued)
Cause
Correction
Check the flow through the fuel filter. Replace
the fuel filter if necessary. Refer to Procedure
Fuel filter or fuel inlet restriction
.......
006-015. Clean all prefilters and screens.
Check the fuel suction line for restriction.
OK
F
Check the fuel drain lines for restriction. Clear
or replace the fuel lines, check valves, or tank
uel drain line is restricted
.......
vents as necessary. Refer to Procedure
006-012.
OK
F
Inspect the fuel transfer pump. Replace if
uel transfer pump malfunctioning
.......
necessary. Refer to Procedure 005-045.
OK
F
uel pump return overflow valve is malfunction-
Inspect the return overflow valve. Replace if
.......
necessary. Refer to Procedure 006-044.
ing
OK
L
ubricating oil level is above or below specifi-
Check the oil level. Add or drain oil, if neces-
.......
sary. Refer to Procedure 007-043.
cation
OK
P
Inspect the air cleaner element. Replace as
needed. Refer to the OEM service manual or
lugged air filter
.......
the Operation and Maintenance Manual, B
Series Engines, Bulletin No. 3810205.
OK
I
If the vehicle is equipped with a valve switch
ntake air source is incorrect
.......
the intake source from under the hood to
outside, position and valve for the season.
OK
A
Tighten the fittings, repair plumbing, replace
wastegate diaphragm. Refer to Procedure
ir fuel tube leaking, wastegate diaphragm
.......
010-050 or the Turbocharger Master Repair
ruptured, or wastegate plumbing damaged
Manual, Bulletin No. 3580555.
OK
B
(Continued)
L-627
