2008 MITSUBISHI LANCER EVOLUTION X air condition

FUEL INJECTION CONTROL
MULTIPORT FUEL SYSTEM (MFI)13A-31
Additional Fuel Injection During Acceleration
In addition to the synchronizing fuel injection with crankshaft
position sensor signal during acceleration, the volume of fuel is
injected according to the extent of the acceleration.
2. Fuel injection volume (injector drive time)
control
The figure shows the flow for injector drive time calculation.
Basic drive time is decided based on the mass airflow sensor
signal (intake air volume signal) and crankshaft position sensor
signal (engine rotation signal). This basic drive time is compen
-
sated according to signals from various sensors and optimum
injector drive time (fuel injection volume) is calculated accord
-
ing to driving conditions.
AK604623
H
L
AB
Cylinder stroke
No. 1 Cylinder
No. 3 Cylinder
No. 4 Cylinder
No. 2 CylinderCombustion
Intake
Exhaust
CombustionExhaust
Compression
Intake
Exhaust CompressionCombustion
Intake CompressionIntake
Exhaust
Combustion
Compression Crankshaft
position sensor
signal
Increase injection for acceleration

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.

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

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

EVAPORATIVE EMISSION CONTROL SYSTEM INCORRECT PURGE FLOW MONITOR
MULTIPORT FUEL SYSTEM (MFI)13A-52
EVAPORATIVE EMISSION CONTROL SYSTEM INCORRECT
PURGE FLOW MONITOR
M2132027200019
The ECM detects whether the fuel vapor leakage
exists or not from the evaporative emission control
system. By the specified pattern within the certain
operation range, the ECM drives the evaporative
emission purge solenoid and the evaporative emis
-
sion ventilation solenoid. This allows slight vacuum
to be produced in the fuel tank.
The ECM measures the vacuum condition through
the fuel tank differential pressure sensor signal. By
comparing the normal (expected) value and the
actual value, the ECM detects whether the fuel vapor
leakage exists or not from the evaporative emission
control system.
AK604139
Evaporative emission
purge solenoid
Evaporative emission
ventilation solenoid
Fuel tank differential pressure sensor
Fuel tank temperature sensor
AB
BatteryMFI relay
ECM Mass airflow sensor
Barometric pressure sensor
Intake air temperature sensor
Engine coolant
temperature sensor
Fuel level sensor (CAN)Fuel
tank
Fuel level
sensor To injector