Defective starting motor
External fuel leak
Improper injection timing
Oil pressure high
Loose fan belt
Clogged fuel tank vent hole
Defective regulator
Battery full charge
Starter motor mounting bolt loose
Defective alternator
Defective thermostat valve
Clogged fuel filter
Defective pressure relief valve
Clogged silencer
Air in fuel system
Water in fuel system
Defective oil pump
Defective starter switch
Improper valve timing
No water in fuel