3.1
3
Section 3
Troubleshooting
Troubleshooting Guide
When troubles occur, be sure to check the simple
causes which, at
fi
rst, may seem too obvious to be
considered. For example, a starting problem could be
caused by an empty fuel tank.
Some general common causes of engine troubles are
listed below. Use these to locate the causing factors.
Refer to the speci
fi
c section(s) within this service
manual for more detailed information.
Engine Cranks But Will Not Start
1. Empty fuel tank.
2. Fuel shut-o
ff
valve closed.
3. Poor fuel, dirt or water in the fuel system.
4. Clogged fuel line.
5. Spark plug lead(s) disconnected.
6. Key switch or kill switch in OFF position.
7. Faulty spark plugs.
8. Faulty ignition coil(s).
9. Vacuum fuel pump malfunction, or oil in vacuum
hose.
10. Vacuum hose to fuel pump leaking or cracked.
11. Ba
tt
ery connected backwards.
12. Safety interlock system engaged.
13. Blown fuse.
14. Faulty electronic control unit.
15. Insu
ffi
cient voltage to electronic control unit.
Engine Starts But Does Not Keep Running
1. Restricted fuel tank cap vent.
2. Poor fuel, dirt or water in the fuel system.
3. Faulty or improperly adjusted thro
tt
le controls.
4. Loose wires or connections.
5. Faulty cylinder head gasket.
6. Vacuum fuel pump malfunction, or oil in vacuum
hose.
7. Vacuum hose to fuel pump leaking or cracked.
8. Intake system leak.
9. Faulty ignition coil(s).
10. Blown fuse.
11. Insu
ffi
cient voltage to electronic control unit.
Engine Starts Hard
1. PTO drive is engaged.
2. Dirt or water in the fuel system.
3. Clogged fuel line or fuel
fi
lter.
4. Loose or faulty wires or connections.
5. Faulty or improperly adjusted thro
tt
le controls.
6. Faulty spark plugs.
7. Low compression.
8. Weak spark.
9. Fuel pump malfunction causing lack of fuel.
10. Engine overheated-cooling/air circulation
restricted.
11. Quality of fuel.
12. Flywheel key sheared.
13. Intake system leak.
Engine Will Not Crank
1. PTO drive is engaged.
2. Ba
tt
ery is discharged.
3. Safety interlock switch is engaged.
4. Loose or faulty wires or connections.
5. Faulty key switch or ignition switch.
6. Faulty electric starter or solenoid.
7. Seized internal engine components.
8. Blown fuse.
9. Faulty electronic control unit.
10. Insu
ffi
cient voltage to electronic control unit.
Engine Runs But Misses
1. Dirt or water in the fuel system.
2. Spark plug lead disconnected.
3. Poor quality of fuel.
4. Faulty spark plug(s).
5. Loose wires or connections.
6. Engine overheated.
7. Faulty ignition module.
8. Incorrect cranksha
ft
position sensor air gap.
9. Insu
ffi
cient voltage to electronic control unit.
Engine Will Not Idle
1. Dirt or water in the fuel system.
2. Stale fuel or dirty fuel injectors.
3. Faulty spark plugs.
4. Inadequate fuel supply.
5. Low compression.
6. Restricted fuel tank cap vent.
7. Engine overheated-cooling system/air circulation
problem.
Содержание Command PRO CH749
Страница 1: ...SERVICE MANUAL ECH630 ECH749 HORIZONTAL CRANKSHAFT ...
Страница 2: ......
Страница 4: ......
Страница 76: ...6 6 Section 6 Lubrication System ...
Страница 94: ...7 18 Section 7 Electrical System and Components ...
Страница 112: ...8 18 Section 8 Disassembly ...
Страница 126: ...9 14 Section 9 Inspection and Reconditioning ...
Страница 153: ......