Fuel Control Valve; Fuel Pressure Regulator - Kohler KG2204 Service

1.7. Fuel Control Valve

KG2204
KG2204T
Figure 1-8 Fuel Control Valves
The fuel control valve (FCV) is an electrically controlled
engine vacuum switch. When the FCV is energized,
the valve opens and, through a vacuum line connection
to the fuel regulator, creates a vacuum on the fuel
pressure regulator.
regulator's diaphragm to close, decreasing the fuel
delivered to the intake. The FCV signal is a modulated
signal sent by the ECM to obtain stoichiometric
combustion.
The ECM cycles FCV to provide the rich and lean
transitions required for low exhaust emissions and
peak engine performance. Based on the fuel
requirements of the engine, the ECM sends a signal to
control the amount of time that the fuel control valve is
open. Opening and closing the fuel control valve alters
the fuel pressure delivered from the regulator to the air-
fuel mixer.
When the engine starts, the engine ECM is an "open
loop" state, which means fuel delivery is based on a
fuel calibration program internal to ECM. The program
controls the fuel control valve to achieve stoichiometric
combustion.
After the oxygen sensor heats up and the engine
coolant temperature reaches a predetermined level,
TP-6903 5/16a
This vacuum causes the
the ECM calibration program transitions to a closed-
loop mode. The air/fuel delivery is based on the
oxygen sensor input and engine sensor data. The
engine ECM uses this data to regulate the fuel control
valve (FCV), which is used as a fuel trim device and is
located at the intake manifold.

1.8. Fuel Pressure Regulator

Figure 1-9 Fuel Pressure Regulator
The fuel pressure regulator ensures that the fuel enters
the system at a consistent and usable pressure. The
fuel selection on the pressure regulator can be
manually set for Natural Gas (NG) or Liquefied
Petroleum Gas (LPG).
Fuel System Overview 15