Page 117 of 241

ACTUATOR
MULTIPORT FUEL SYSTEM (MFI)13A-24
THROTTLE ACTUATOR CONTROL MOTOR
A throttle actuator control motor is installed in throttle body. The
throttle actuator control motor performs the Open/Close of the
throttle valve through the reduction gear. ECM changes current
direction according to the Open/Close direction and also
changes current to the motor coil to control the throttle actuator
control motor.
Throttle actuator control motor is composed of a good
response, low energy, and small DC motor with brush and can
generate rotation force corresponding to the current applied on
the coil. When there is no current passing through the throttle
actuator control motor, the throttle valve remains at a pre
-
scribed opening angle. So, even if current stops because of a
fault in the system, a minimum level of running remains possi
-
ble.
AK604125AB
Throttle body
Throttle actuator
control motor
AK602231
Throttle actuator
control motor
Throttle actuator
control motor relayMFI relay
To ECM
Power supplyOFFON
OFF
ON
AE
From battery
ECM
Page 121 of 241
ACTUATOR
MULTIPORT FUEL SYSTEM (MFI)13A-28
GENERATOR G TERMINAL
ECM uses ON/OFF of generator G terminal to control genera-
tor output voltage. When the power transistor in the ECM turns
ON, output voltage gets adjusted to about 12.8 V. When gener
-
ator output voltage drops to 12.8 V it becomes lower than volt-
age of the charged battery and almost no current is output from
the generator. When the power transistor in the ECM turns
OFF, output voltage gets adjusted to about 14.7 V. When gen
-
erator output voltage is about 14.7 V, generator outputs current
to produce electricity. In case electric load is generated sud
-
denly, ECM controls generator G terminal's On-duty to limit the
sudden increase in generator load due to generation and thus
prevents change in idle speed.
AK602233AD
Field coil
IC regulator
GeneratorG Ignition switch-IG
Battery
BS
ECM
Page 125 of 241
FUEL INJECTION CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-32
Fuel Injection Volume Control Block Diagram
.
AK602278AD
Mass airflow sensor
Crankshaft
position sensor
Heated oxygen
sensor
Engine coolant
temperature
compensation Engine coolant
temperature sensor
Manifold absolute
pressure sensorFuel pressure
compensation Barometric pressure
sensor
Battery voltage
compensation Battery voltageBasic fuel
injection time
determinationAir fuel ratio
compensation
(Predetermined
compensation)
Heated oxygen
sensor feedback
compensation
Injector Acceleration-
deceleration
compensation
Page 127 of 241
![MITSUBISHI LANCER EVOLUTION X 2008 Workshop Manual FUEL INJECTION CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-34
[Injector drive time compensation]
After calculating the injector basic drive time, the ECM makes
the following compensations to control the o MITSUBISHI LANCER EVOLUTION X 2008 Workshop Manual FUEL INJECTION CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-34
[Injector drive time compensation]
After calculating the injector basic drive time, the ECM makes
the following compensations to control the o](/manual-img/19/57326/w960_57326-126.png)
FUEL INJECTION CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-34
[Injector drive time compensation]
After calculating the injector basic drive time, the ECM makes
the following compensations to control the optimum fuel injec
-
tion volume according to driving conditions.
List of main compensations for fuel injection control
.
[Fuel limit control during deceleration]
ECM limits fuel when decelerating downhill to prevent exces-
sive rise of catalytic converter temperature and to improve fuel
efficiency.
.
[Fuel-cut control when over-run]
When engine speed exceeds a prescribed limit (6,600 r/min),
ECM cuts fuel supply to prevent overrunning and thus protect
the engine. Also, if engine speed exceeds 4,000 r/min for 15
seconds while vehicle is stationary (no load), it cuts fuel supply
and controls the throttle valve opening angle to protect the
engine.
CompensationsContent
Heated oxygen sensor feedback compensationThe heated oxygen sensor signal is used for
making the compensation to get air-fuel ratio with
best cleaning efficiency of the 3-way catalytic
converter. This compensation might not be made
sometimes in order to improve drivability,
depending on driving conditions. (Air-fuel ratio
compensation is made.)
Air-fuel ratio compensationUnder driving conditions where heated oxygen
sensor feedback compensation is not performed,
compensation is made based on pre-set map
values that vary according to engine speed and
intake air volume.
Engine coolant temperature compensationCompensation is made according to the engine
coolant temperature. The lower the engine coolant
temperature, the greater the fuel injection volume.
Acceleration/ Deceleration compensationCompensation is made according to change in
intake air volume. During acceleration, fuel injection
volume is increased. Also, during deceleration, fuel
injection volume is decreased.
Fuel injection compensationCompensation is made according to the pressure
difference between atmospheric pressure and
manifold absolute pressure. The greater the
difference in pressure, the shorter the injector drive
time.
Battery voltage compensationCompensation is made depending on battery
voltage. The lower the battery voltage, the greater
the injector drive signal time.
Learning value for fuel compensationCompensation amount is learned to compensate
feedback of heated oxygen sensor. This allows
system to compensate in accordance with engine
characteristics.
Page 128 of 241
IGNITION TIMING AND CONTROL FOR CURRENT CARRYING TIME
MULTIPORT FUEL SYSTEM (MFI)13A-35
IGNITION TIMING AND CONTROL FOR CURRENT
CARRYING TIME
M2132027100089
Ignition timing is pre-set according to engine driving
conditions. Compensations are made according to
pre-set values depending on conditions such as
engine coolant temperature, battery voltage etc. to
decide optimum ignition timing. Primary current con
-
nect/disconnect signal is sent to the power transistor
to control ignition timing. Ignition is done in sequence
of cylinders 1, 3, 4, 2.
System Configuration Diagram
AK502722AD
ECM MFI relay
Spark plugs Ignition
coils
Cylinder No. 1 2 3 4Battery
Mass airflow sensor
Intake air temperature sensor
Manifold absolute
pressure sensor
Engine coolant
temperature sensor
Intake camshaft position sensor
Exhaust camshaft position sensor
Crankshaft position sensor
Knock sensor
Ignition switch-ST Throttle position sensor
Page 130 of 241
![MITSUBISHI LANCER EVOLUTION X 2008 Workshop Manual IGNITION TIMING AND CONTROL FOR CURRENT CARRYING TIME
MULTIPORT FUEL SYSTEM (MFI)13A-37
2. Spark-advance control and current carrying
time control
.
[During start]
ECM initiates ignition at fixed ign MITSUBISHI LANCER EVOLUTION X 2008 Workshop Manual IGNITION TIMING AND CONTROL FOR CURRENT CARRYING TIME
MULTIPORT FUEL SYSTEM (MFI)13A-37
2. Spark-advance control and current carrying
time control
.
[During start]
ECM initiates ignition at fixed ign](/manual-img/19/57326/w960_57326-129.png)
IGNITION TIMING AND CONTROL FOR CURRENT CARRYING TIME
MULTIPORT FUEL SYSTEM (MFI)13A-37
2. Spark-advance control and current carrying
time control
.
[During start]
ECM initiates ignition at fixed ignition timing (5° BTDC) syn-
chronized with the crankshaft position sensor signal.
.
[During normal operation]
After determining the basic spark-advance based on the intake
air volume and engine speed, ECM makes compensations
based on input from various sensors to control the optimum
spark-advance and current carrying time.
List of main compensations for spark-advance control and current carrying time control
.
[Control for checking ignition timing]
During basic ignition timing set mode for M.U.T.-III actuator test
function, sparking is done with fixed ignition timing (5
° BTDC)
synchronized with crankshaft position sensor signal.
CompensationsContent
Intake air temperature compensationCompensation is made according to intake air
temperature. The higher the intake air temperature
the greater the delay in ignition timing.
Engine coolant temperature compensationCompensation is made according to engine coolant
temperature. The lower the engine coolant
temperature the greater the advance in ignition
timing.
Knocking compensationCompensation is made according to generation of
knocking. The greater the knocking the greater the
delay in ignition timing.
Stable idle compensationCompensation is made according to change in idle
speed. In case engine speed becomes lower than
target speed, ignition timing is advanced.
Delay compensation when changing shiftDuring change of shift, sparking is delayed
compared to normal ignition timing to reduce
engine output torque and absorb the shock of the
shift change.
Battery voltage compensationCompensation is made depending on battery
voltage. The lower the battery voltage the greater
the current carrying time and when battery voltage
is high current carrying time is shortened.
Page 138 of 241
MULTIPORT FUEL INJECTION (MFI) RELAY CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-45
MULTIPORT FUEL INJECTION (MFI) RELAY CONTROLM2132006000173
When the ignition switch-IG "ON" signal is input,
ECM turns ON the power transistor for control of the
MFI relay. As a result, current flows through the MFI
relay's coil, the relay switch turns ON and power is
supplied to each sensor and actuator. Also, when
ignition switch-IG "OFF" signal is input, ECM per
-
forms the following controls and then turns OFF the
power transistor for control of MFI relay.
•Throttle valve initializing control
AK604134AB OFF
ON
IG2 STLOCK
ACC
IG1
MFI relay
Power
supply
MFI relay control Ignition switch-IGBattery
back up To each sensor and
actuatorIgnition switch
ETACS-ECU Battery
ECM
Page 139 of 241
FUEL PUMP RELAY CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-46
FUEL PUMP RELAY CONTROLM2132006500208
When current flows through the fuel pump relay, the
relay turns ON and the fuel pump is driven. The fuel
pump relay is built into the ETACS-ECU. When the
ignition switch-ST signal is input, ECM turns ON the
power transistor for control of the fuel pump relay. As a result, power is supplied to the fuel pump. Also, if
engine speed falls below a set value, the fuel pump
relay is turned OFF. Thus, it deals with sudden stop
-
pages such as engine stalling etc. by stopping the
pump.
AK604135
M
OFF
ON
OFF
ON
AB IG2 STLOCK
ACC
IG1
ETACS
-ECUMFI
relay
ECM Fuel pumpFuel pump
relay
Crankshaft position sensor Ignition switch
To ECM
Ignition switch-ST Battery
Fuel pump
relay control