TM 5-3805-260-24
4.
SUDDEN CHANGES IN ENGINE RPM
Cause
Correction
Air In The Fuel System
Find the air leak in the fuel system and correct it. Iloosen each fuel line nut at the
injection pumps and open the manual bleed Nalec. Loosen the bolts that hold the
torque spring or stop bar cover. This will let out any air that is in the governor
housing. After all air is out of fuel system, tighten bolts that hold torque spring or
stop bar cover. Tighten fuel line nuts according to the SPECIFICATIONS. Close
manual bleed valve.
Broken Torsion Spring on
Install new parts as needed.
Sleeve Control Shaft
Linkage In Governor Does
Clean all linkage and inside of governor housing. Install new
Not Move Freely
parts for those parts that have damage.
Governor Springs Not
Put springs completely on spring seat.
Completely on Spring Seat
Spring for Dashpot
Install spring correctly.
Governor Installed Wrong
5. NOT ENOUGH POWER
Cause
Correction
Bad Quality Fuel
Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good
grade of clean fuel in the fuel tank.
Fuel Pressure is Low
Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line
between fuel tank and fuel transfer pump. Look for air in the fuel system. Check
fuel pressure. The outlet pressure of the fuel transfer pump at full load speed is 30
+ 5 psi (205 + 35 kPa). If fuel pressure is lower than above pressure, install a new
fuel filter element. Inspect the fuel bypass salve for free movement. Install a new
fuel bypass valve if necessary.
Air In The Fuel System
Find the air leak in the fuel system and correct it. Loosen each fuel line nut at the
injection pumps and open the manual bleed valve. Loosen the bolts that hold the
torque spring or stop bar cover. This will let out any air that is in the governor
housing. After all air is out of fuel system, tighten bolts that hold torque spring or
stop bar cover. Tighten fuel line nuts according to the SPECIFICATIONS. Close
manual bleed valve.
Air Inlet Has A
Check air inlet pipes and air cleaner for restrictions.
Restriction
Wrong Fuel Setting
Make adjustments as necessary.
Governor Linkage
Make adjustment to get full travel of linkage. Install new parts for those that have
damage or defects.
Defect in Timing
Replacement of timing advance unit is needed.
Advance Unit
2-26
