Installation manual

THROTTLE BODY ASSEMBLY
TO
SCHRADER
VALVE
STEPPER MOTOR
MAP SENSOR
FROM THE THERMOSTAT ASSEMBLY
c:-i"
DESCRIPTION
FUEL INJECTOR
The above illustration shows the throttle body assembly
attached to the intake manifold.
An electronic control unit (ECU) controls the fuel injector
and the throttle actuator.
The ECU
is supplied with engine operating conditions from
sensors that monitor intake air temperature, engine coolant
temperature, map sensor (intake manifold absolute pressure),
engine rpm and battery voltage.
The ECU interprets this information to determine the
appropriate injector pulse rate and throttle opening position.
A high pressure fuel pump supplies fuel to the area around
the injector and the regulator maintains the fuel pressure in
that area at 35 -
40 PSI.
FUEL
PRESSURE
REGULATOR
PVC VALVE
The injector is a solenoid operated pintle valve that meters
fuel into the intake manifold depending on engine operating
conditions and generator amperage load as determined by the
ECU.
Air flow into the intake manifold
is through the flame
arrester/air filter and
is controlled by the ECU operation of
the throttle plate via the actuator. Throttle plate positioning
for proper air flow into the engine
is accomplished through
· the ECU interpretation of engine operating conditions. The
Schrader valve is used to monitor/check fuel pressure around
the fuel injector and to bleed air from that area after fuel
system servicing.
20
An air intake heater is positioned in the intake to heat the
incoming air during a cold start.