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1881-01
ENGINE FUEL SYSTEM
OVERVIEW AND OPERATION PROCESS
1. ELECTRONIC CONTROL OF FUEL SYSTEM
According to input signals from various sensors, engine ECU calculates driver's demand
(position of the accelerator pedal) and then controls overall operating performance of engine
and vehicle on that time.
ECU receives signals from sensors via data line and then performs effective engine air-fuel
ratio controls based on those signals. Engine speed is measured by crankshaft speed (position)
sensor and camshaft speed (position) sensor determines injection order and ECU detects
driver's pedal position (driver's demand) through electrical signal that is generated by variable
resistance changes in accelerator pedal sensor. Air flow (hot film) sensor detects intake ai
r
volume and sends the signals to ECU. Especially, the engine ECU controls the air-fuel ratio by
recognizing instant air volume changes from air flow sensor to decrease the emissions (EGR
valve control). Furthermore, ECU uses signals from coolant temperature sensor and ai
r
temperature sensor, booster pressure sensor and atmospheric pressure sensor as
compensation signal to respond to injection starting, pilot injection set values, various
operations and variables.Components
High pressure fuel pump
Fuel injectors -
-Fuel rail
Electronic control unit(ECU) -
-Fuel pressure sensor
Various sensors and actuators -
-Supply line
Return line
ECU connecting line
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2321-01
ENGINE INTAKE SYSTEM
1. EGR pipe (RH) 5. Exhaust gas
2. EGR pipe (center) 6. EGR pipe (LH)
3. Coolant emission port 7. Vacuum modulator to the EGR valve
4. Intake air (intercooler)
Intake Manifold
Incoming of intake air and
exhaust gas (Operation o
f
EGR valve) Incoming of intake air (No
operation of EGR valve)
Coolant
emission port
Coolant
emission port The SUS + Rubber coating is applied to the intake manifold gasket to prevent the air leakage
and optimize the sealing effect.
Intake airIntake air
Exhaust gas
