Hunting And Surging - Kohler KG2204 Service

3.11. Hunting and Surging

Definition: The engine has a power variation under a
steady throttle. The engine feels as if it speeds up and
slows down with no change to the throttle.
Checks
Preliminary Checks
Sensor Checks
Fuel System Checks
Ignition System Checks
Additional Check
Figure 3-13 Hunting and Surging Troubleshooting
TP-6903 5/16a
Action
None.
Check the Heated Exhaust Gas Oxygen Sensor (HEGO) performance.
 Check for rich or lean symptom that causes the condition.
 While running the engine, monitor the HEGO sensor.
 Check the fuel pressure while the condition exists.
 Verify proper fuel control shut-off valve operation.
 Verify that the fuel supply valve on the gas supply line is fully open.
 Check for proper ignition output voltage with a spark tester.
 Verify that the spark plugs are the correct type and properly gapped.
 Remove the plugs and inspect them for the following conditions:
o Wet plugs (oil fouling).
o Cracks.
o Wear.
o Improper gap.
o Burned electrodes.
o Heavy deposits.
 Check the Crankshaft Position (CKP) sensor.
 Check that the ECM grounds are clean, tight, and in their proper locations.
 Check the alternator output voltage.
 Check the vacuum hoses for kinks or leaks.
Fuel System Troubleshooting 57