2008 MITSUBISHI LANCER EVOLUTION X Workshop Manual

MIVEC (Mitsubishi Innovative Valve Timing Electronic Control System)
MULTIPORT FUEL SYSTEM (MFI)13A-44
Within range of low
speed and high load
at accelerationAdvancing closing timing of
intake valve allows amount
of intake air flowing back
into intake port to be limited
as well as allows
volumetric efficiency to be
improved, resulting in low
and middle speed torques
improved.Low and middle speed
torques improved
Within range of
middle speed and
middle loadIncreasing overlap amount
allows pumping loss to be
decreased. Retarding
opening timing of exhaust
valve allows burned gas to
work sufficiently and allows
cycle efficiency to be
improved, resulting in
higher expansion ratio.Fuel economy
improved
Within range of high
speed and high loadRetarding closing timing of
intake valve in accordance
with engine speed allows
valve timing to be
controlled according to
inertia force of intake air
and allows volumetric
efficiency to be improved.Output improved
Operation condition Valve timing Operation Effectiveness
AK604131AB
TDC
BDC Exhaust valveIntake valve
Open
Close
AK604132AB
TDC
BDC Exhaust valve
Intake valve Overlap:
large
Open
AK604133
TDC
BDC
AB
Exhaust valveIntake valve
Close

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

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

STARTER RELAY CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-47
STARTER RELAY CONTROLM2132025500092
AK604136
M
AB OFF ON OFF
ON
Engine-ECU
Starter relay
controlClutch
interlock
switch
ETACS
-ECUIgnition switch-STBattery
Starter relay
Starter
OFFON

STARTER RELAY CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-48
When the ignition switch-ST signal is input, ECM
turns ON the power transistor for control of the
starter relay.
AK604137
M
AB P
DNR
OFF ON OFF
ON
Engine-ECU
Starter relay
controlTransmission
range switch Ignition switch-STBattery
Starter relay
Starter ETACS
-ECU

HEATED OXYGEN SENSOR HEATER CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-49
HEATED OXYGEN SENSOR HEATER CONTROLM2132007000206
When exhaust gas temperature is low, the heated
oxygen sensor response is dull. So, response is
improved by raising the sensor temperature by pass
-
ing current through the heater at a low exhaust gas
temperature, such as in the immediate aftermath of
the engine start, or during the warm up operation and in cutting the fuel during deceleration. Based on driv
-
ing conditions and the heated oxygen sensor activa-
tion state, ECM changes the amount of current (duty
ratio) to the heater to quicken the activation of the
heated oxygen sensor.
AK602241AD
Battery Heated oxygen sensor heater
Engine coolant
temperature sensor MFI relay
ECM

A/C COMPRESSOR RELAY CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-50
A/C COMPRESSOR RELAY CONTROLM2132034500120
The ECM turns on the power transistor when the A/C
switch ON signal is input by the A/C-ECU through
the CAN. This allows the A/C compressor relay to be
ON and to be operated. During the high load opera
-
tion, such as the acceleration with the fully opened
accelerator, the ECM secures the acceleration capa
-
bility by turning off the A/C compressor relay for the
specified period to produce no load on the A/C com
-
pressor.
AK604138
OFF
ON
AB
Battery
A/C compressor relay
A/C compressor
assembly
A/C compressor
relay control A/C compressor
clutch
A/C
refrigerant
temperature
switch
OFF ON
A/C switch (CAN)
ECM

GENERATOR CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-51
GENERATOR CONTROLM2132025000172
During engine idle operation, ECM controls duty of
conduction between generator G terminal and
ground. (G terminal duty is controlled to be the same
as ON duty of the power transistor inside the voltage
regulator). If headlights etc. are turned on while
engine is idling, the consumed current increases
suddenly, but by gradually increasing the generator G terminal OFF duty, ECM restricts sudden increase
in generator's output current and output current is
increased only gradually. (Battery current is supplied
to the headlamp etc. till generator produces sufficient
current.) Thus, ECM prevents change in idle speed
due to sudden increase of engine load.
AK602242 AD
Engine coolant temperature sensor
Generator G terminal
Generator FR terminal
Generator Crankshaft position sensor
A/C switch (CAN)
Ignition switch-STECM