Kohler Command PRO ECH630 Service Manual page 25

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 specifi c section(s) within this service
manual for more detailed information.
Engine Cranks But Will Not Start
1. Empty fuel tank.
2. Fuel shut-off 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. Batt ery connected backwards.
12. Safety interlock system engaged.
13. Blown fuse.
14. Faulty electronic control unit.
15. Insuffi 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 thrott 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. Insuffi cient voltage to electronic control unit.
Engine Starts Hard
1. PTO drive is engaged.
Section 3
Troubleshooting
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 thrott 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
11. Quality of fuel.
12. Flywheel key sheared.
13. Intake system leak.
Engine Will Not Crank
1. PTO drive is engaged.
2. Batt 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. Insuffi 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 crankshaft position sensor air gap.
9. Insuffi 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
restricted.
problem.
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