TM 55-2840-254-23
1-33 TROUBLESHOOTING PROCEDURES
Engine trouble can be either obvious or hidden. If hidden troubles are not detected, serious and consider-
able damage may occur to the engine. Therefore, it is essential to have a thorough knowledge of the cor-
rect power turbine inlet temperature, fuel flow, lubrication oil pressure, and other important details of
normal engine operation.
It is essential to have information of previous trouble and work performed on the engine. Check each pos-
sible source of trouble until the trouble has been isolated by a process of elimination. Systematic checking
is essential for thorough troubleshooting. it saves time and promotes accuracy. If the symptom also con-
tains a visual check, always perform the visual check first. In all troubleshooting tasks, if fault cannot be
corrected by the end of the task the engine is to be replaced.
Tasks 1-34 thru 1-73 contain troubleshooting procedures to be used for isolating and correcting engine
problems. The symptom is the task title and appears at the top of the task. A logic tree flow chart is used
in conjunction with locator illustrations to assist troubleshooting. To use the flow chart, start at the first
left-hand box. Follow all instructions, answer all questions and proceed through chart as indicated. Use
locator illustrations as needed and proceed through chart until symptom has been corrected.
LIST OF TASKS
NUMBER
TITLE
Starter Drive Does Not Turn Engine or Engine Cranking Speed is Too Slow
Engine Does Not Start - No Snapping Sound is Heard When Starting
System is Activated
No Combustion During Start - Ignition System Normal - Visual Check
No Combustion During Start - Ignition System Normal
Torching Starts - Visual Check
Torching Starts
With Power Lever (N1) in Ground Idle Position, Engine Does Not Reach Ground
Idle Speed - Visual Check
With Power Lever (N1) in Ground Idle Position, Engine Does Not Reach Ground
Idle Speed
Ground Idle Speed is Incorrect - Visual Check
1-121
