Kohler COMMAND CH18, Service Manual

Page: 95 / 232

5B.26
Section 5B
EFI Fuel System
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-37. 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.
Troubleshooting Guide
Engine starts hard or fails to start when cold
1. Fuel pump not running
2. Faulty spark plugs
3. Old/stale fuel
4. Incorrect fuel pressure
5. Speed sensor loose or faulty
6. TPS offset incorrect (initialization)
7. TPS faulty
8. Engine temperature sensor faulty
9. Faulty coils
10. Low system voltage
11. Faulty injectors
Engine starts hard or fails to start when hot
1. Faulty spark plugs
2. Fuel pump not running
3. Fuel pressure low
4. Insufficient fuel delivery
5. TPS offset incorrect (Initialization)
6. Speed sensor loose or faulty
7. TPS faulty
8. Engine temperature sensor faulty
9. Faulty injectors
Engine stalls or idles roughly (cold or warm)
1. Faulty spark plugs
2. Insufficient fuel delivery
3. TPS offset incorrect
4. TPS faulty
5. Faulty engine temperature sensor
6. Faulty injectors
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)