TM 5-3825-226-24
ENGINE TROUBLESHOOTING CHART
1. ENGINE WILL NOT START
Cause
Correction
Empty Fuel Tank
Put fuel in fuel tank.
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.
Dirty Fuel Filter
Install new fuel filter.
Dirty or Broken Fuel Lines
Clean or install new fuel lines as necessary.
Linkage to Sleeve Control
Check the operation of the shut-off solenoid and the shut-off
Shaft is Held in Shutoff
linkage. Solenoid must pull up to compress spring for fuel turn on.
Position
Check governor linkage for free movement. Sleeves must turn
freely on pump plungers in all positions of sleeve control shaft.
The thrust collar must turn freely on the governor shaft at all
positions between shut-off and full load. If linkage does not move
freely under these conditions, clean all parts thoroughly. Inspect
all parts for wear and make replacement where needed.
Fuel Pressure is Too Low
Replace the fuel filter. Inspect the bypass valve for free move-
ment. Install a new 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.
Fuel System Not Timed
Make adjustment to timing if necessary.
Correctly to Engine
Constant Bleed Valve Stays
Replace constant bleed valve.
Open (Not enough fuel
pressure for starting)
No Over Fueling Spring
Install an over fueling spring.
2. MISFIRING OR RUNNING ROUGH
Cause
Correction
Fuel Pressure is Low
Make sure there is enough 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 valve for free movement.
Install a new fuel bypass valve if necessary.
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