Hesitation, Sag, Or Stumble - Kohler KG2204 Service

3.6. Hesitation, Sag, or Stumble

Definition: The engine has a momentary lack of
response when accelerating. The condition can occur
at any engine speed. The condition may cause the
engine to stall if it's severe enough.
Checks
Preliminary Checks
Fuel System Checks
Ignition System Checks
Additional Check
Figure 3-8 Hesitation, Sag, or Stumble Troubleshooting
52 Fuel System Troubleshooting
Action
None.
 Check the fuel pressure.
 Check for low fuel pressure during a moderate or full throttle acceleration. If the fuel
pressure drops below specification, there is possibly a faulty fuel pressure regulator or a
restriction in the fuel system.
 Check the TMAP sensor response and accuracy.
 Check shut-off electrical connections.
 Check the fuel pressure regulator, air-fuel mixer and throttle body for proper installation
and leakage.
 Check for proper ignition output voltage with a spark tester.
 Verify that the spark plugs are the correct type and properly gapped.
 Check for faulty spark plug leads.
 Check for oil-fouled spark plugs.
 Check for manifold vacuum or air induction system leaks.
 Check the alternator output voltage.
 Check for air intake system leakage at all connections between the air-fuel mixer and
throttle body.
 Check for charge air cooler leaks on turbocharged engines.
 Check for sticking of the turbocharger wastegate.
TP-6903 5/16a