Hard Starting Symptoms and Probable Causes
Probable Causes
Low Battery Voltage
Loose cranking motor
connections
Faulty cranking motor
Faulty cranking motor switch
Internal seizure
Improper lube oil
Circuit breaker/electronic control
Fuse blown or missing
Insufficient Fuel Supply
Air in fuel
Out of fuel
Loose fuel connections
Cracked fuel lines
Obstructed fuel filters/lines
Faulty fuel pump
Restricted fuel fitting missing
Installation/operation of fuel
check valve or shutoff valve
Worn intake and exhaust valves
Worn piston rings/liners
Leaking cylinder head gasket
Improper intake or exhaust valve
adjustments
All information subject to change without notice.
DDC-SVC-MAN-0039
SERIES 60 ON-HIGHWAY ENGINE OPERATOR'S GUIDE
Engine Will
Not Rotate
Copyright © 2009 DETROIT DIESEL CORPORATION
Low
Cranking
Speed
X
X
-
X
X
X
X
X
-
X
-
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Engine
Cranks But
Will Not
Start
-
-
-
X
-
-
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
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