Kohler LH630-775 Service Manual page 77

Engine idles too fast (after full warm-up).
1. Throttle linkage binding or not returning to idle
position.
2. Idle speed adjustment incorrect.
3. Vacuum (intake air) leak.
4. Leaking fuel injector O-Rings (injector to
manifold).
5. Engine (Coolant) Temperature sensor faulty.
6. TPS faulty or "TPS Initialization Procedure."
incorrect.
7. Base ignition timing incorrect.
Engine misses, hesitates, or stalls under load. (Code
22, 31, 34, 43, 44, 51, 52)
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.
9. Base ignition timing incorrect.
Low Power. (51, 52)
1. Throttle plates in throttle body/intake manifold
not fully opening to WOT stop (if so equipped).
2. Insufficient fuel delivery.
3. Dirty air filter.
4. Faulty/malfunctioning ignition system.
5. TPS faulty or mounting problem.
6. Basic engine problem exists.
7. Improper governor adjustment.
8. Plugged/restricted exhaust.
9. One injector not working.
10. One spark plug, coil, or wire not working.
Section 5B
EFI Fuel System
5B.37
5B