Troubleshooting - Kohler LH630-775 Service Manual

Section 5B
EFI Fuel System
3. Insert a nail into the hole in the top of the cross
shaft. Using light pressure, rotate the governor
shaft counterclockwise as far as it will turn, then
torque the hex nut on the clamping screw to
6.8 N·m (60 in. lb.). See Figure 5B-34. Make sure
that the governor arm has not twisted up or
down after the nut has been tightened.
Figure 5B-34. Adjusting Governor Shaft.
4. Verify that the governor has been set correctly.
With the linkage still retained in the "Full
Throttle" position (Step 2), unsnap the bushing
clip, separate the linkage from the bushing, and
remove the bushing from the lever. Follow Steps
3 and 4 in ''Checking the Initial Adjustment''.
5. Reconnect the dampening spring into its
governor lever hole from the bottom. Reinstall
the bushing and reattach the throttle linkage. See
Figure 5B-30. Reattach the governor spring in the
marked hole.
6. Start the engine and allow it to fully warm up
and establish closed loop operation
(approximately 5-10 min.). Check the speed
settings and adjust as necessary, first the low
idle speed, and then the high speed setting.

Troubleshooting

General
When troubleshooting a problem on an engine with
EFI, basic engine operating problems must be
eliminated first before faulting the EFI system
components. What appears to be an EFI problem
could be something as simple as a fuel tank with
debris in the bottom or a plugged vent. Be sure the
engine is in good mechanical operating condition and
all other systems are functional before attempting to
troubleshoot the EFI system.
5B.22
Troubleshooting Guide
Engine starts hard or fails to start when cold
1. Fuel pump not running
2. Engine temp sensor faulty
3. Incorrect fuel pressure
4. TPS faulty
5. TPS offset incorrect
6. Old/stale fuel
7. Low system voltage
8. Speed sensor loose or faulty
9. Faulty injectors
10. Faulty coils
11. Faulty spark plugs
Engine starts hard or fails to start when hot
1. Fuel pressure low
2. Fuel pump not running
3. Engine temp sensor faulty
4. Insufficient fuel delivery
5. TPS faulty
6. TPS offset incorrect
7. Speed sensor loose or faulty
8. Faulty injectors
9. Faulty spark plugs
Engine misses, hesitates, or stalls under load
1. Fuel injector(s), fuel filter, fuel line, or fuel pick-up
dirty/restricted
2. Dirty air cleaner
3. Insufficient fuel pressure or fuel delivery
4. Vacuum (intake air) leak
5. Improper governor setting, adjustment or
operation
6. Speed sensor malfunction
7. TPS faulty, mounting problem or "TPS
Initialization Procedure" incorrect
8. Bad coil(s), spark plug(s), or wires
Low Power
1. Faulty/malfunctioning ignition system
2. Dirty air filter
3. Insufficient fuel delivery
4. Improper governor adjustment
5. Plugged/restricted exhaust
6. One injector not working
7. Basic engine problem exists
8. TPS faulty or mounting exists
9. Throttle plates in throttle body/intake manifold
not fully opening to WOT stop (if so equipped)