2007 MITSUBISHI LANCER EVOLUTION Service Repair Manual

ENGINE AND EMISSION CONTROL -Emission Control System17-7
VACUUM HOSE CHECK
1. Using the piping diagram as a guide, check to be sure
that the vacuum hoses are correctly connected.
2. Check the connection condition of the vacuum hoses,
(removed, loose, etc.) and check to be sure that there
are no bends or damage.
VACUUM HOSE INSTALLATION
1. When connecting the vacuum hoses, they should be
securely inserted onto the nipples.
2. Connect the hoses correctly, using the vacuum hose piping
diagram as a guide.

ENGINE AND EMISSION CONTROL -Emission Control System17-8
CRANKCASE EMISSION CONTROL SYSTEM
GENERAL INFORMATION
The crankcase emission control system prevents
blow-by gases from escaping inside the crankcase
into the atmosphere.
Fresh air is sent from the air cleaner into the
crankcase through the breather hose. The air
becomes mixed with the blow-by gases inside the
crankcase.
The blow-by gas inside the crankcase is drawn
into the intake manifold through the positivecrankcase ventilation (PCV) valve.
The PCV valve lifts the plunger according to the
intake manifold vacuum so as to regulate the flow
of blow-by gas properly. In other words, the blow-by
gas flow is regulated during low load engine
operation to maintain engine stability, while the flow
is increased during high load operation to improve
the ventilation performance.
SYSTEM DIAGRAM
Ventilation hose
PCV valve Breather hose

ENGINE AND EMISSION CONTROL -Emission Control System
PCV valve
17-9
COMPONENT LOCATION
POSITIVE CRANKCASE VENTILATION SYSTEM
CHECK
1. Remove the ventilation hose from the PCV valve.
2. Remove the PCV valve from the rocker cover.
3. Reinstall the PCV valve at the ventilation hose.
4. Start the engine and run at idle.
5. Place a finger at the opening of the PCV valve and check
that vacuum of the intake manifold is felt.
NOTE
At this moment, the plunger in the PCV valve moves
back and forth.
6. If vacuum is not felt, clean the PCV valve or replace
it.
PCV VALVE CHECK
1. Insert a thin rod into the PCV valve from the side shown
in the illustration (rocker cover installation side), and move
the rod back and forth to check that the plunger moves.
2. If the plunger does not move, there is a clogging in the
PCV valve. In this case, clean or replace the PCV valve.
PCV valve
PCV valve

ENGINE AND EMISSION CONTROL -Emission Control System
Vacuum tank
Alternator
Purge control solenoid valve
17-10
EVAPORATIVE EMISSION CONTROL SYSTEM
GENERAL INFORMATION
The evaporative emission control system prevents
fuel vapours generated in the fuel tank from
escaping into the atmosphere.
Fuel vapours from the fuel tank flow through the
fuel tank pressure control valve and vapour
pipe/hose to be stored temporarily in the canister.
When driving the vehicle, fuel vapours stored in
the canister flow through the purge solenoid and
purge port and go into the intake manifold to be
sent to the combustion chamber.When the engine coolant temperature is low or
when the intake air quantity is small (when the
engine is at idle, for example), the engine control
unit turns the purge solenoid off to shut off the
fuel vapour flow to the intake manifold.
This does not only insure the driveability when the
engine is cold or running under low load but also
stabilize the emission level.
SYSTEM DIAGRAM
BatteryIntake air
temperature sensor
Barometric pressure
sensor
Check
valve
Canister
Control
relay
Purge control
solenoid valve
(ON: Open)
Engine-ECUEngine coolant
temperature sensor Air flow sensor
COMPONENT LOCATION

ENGINE AND EMISSION CONTROL -Emission Control System17-11
PURGE CONTROL SYSTEM CHECK
1. Disconnect the vacuum hose (red stripe) from throttle
body and connect it to a hand vacuum pump.
2. Plug the nipple from which the vacuum hose was removed.
3. When the engine is cold or hot, apply a vacuum of 53
kPa, and check the condition of the vacuum.
When engine is cold
(Engine coolant temperature: 40_C or less)
Engine conditionNormal condition
At idleVacuum is maintained
3,000 r/min
When engine is hot
(Engine coolant temperature: 80_C or higher)
Engine conditionNormal condition
At idleVacuum is maintained
3,000 r/min (within 3
minutes after engine starts)Vacuum will leak.
PURGE PORT VACUUM CHECK
1. Disconnect the vacuum hose (red stripe) from the throttle
body purge vacuum nipple and connect a hand vacuum
pump to the nipple.
2. Confirm that the vacuum is approximately constant
regardless of the engine rotation speed.
NOTE
If vacuum changes, it is possible that the throttle body
purge port maybe clogged and require cleaning.
Red stripe
Plug
Throttle body
Red stripe
Throttle body
Vac-
uum
Engine speed (r/min)

ENGINE AND EMISSION CONTROL -Emission Control System17-12
PURGE CONTROL SOLENOID VALVE CHECK
NOTE
When disconnecting the vacuum hose, always make a mark
so that it can be reconnected at original position.
1. Disconnect the vacuum hose from the solenoid valve.
2. Disconnect the harness connector.
3. Connect a hand vacuum pump to nipple (A) of the solenoid
valve (refer to the illustration at left).
4. Check airtightness by applying a vacuum with voltage
applied directly from the battery to the purge control
solenoid valve and without applying voltage.
Battery voltageNormal condition
AppliedVacuum leaks
Not appliedVacuum maintained
5. Measure the resistance between the terminals of the
solenoid valve.
Standard value: 30 - 34Ω(at 20_C)
CHECK VALVE CHECK
Connect a hand vacuum pump to the check valve, apply
vacuum and check the airtightness.
Connected nipple colourNormal condition
BlackVacuum leaks
BrownVacuum is maintained
Battery A

ENGINE AND EMISSION CONTROL -Emission Control System17-13
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
GENERAL INFORMATION
The exhaust gas recirculation (EGR) system lowers
the nitrogen oxide (NOx) emission level. When the
air/fuel mixture combustion temperature is high,
a large quantity of nitrogen oxides (NOx) is
generated in the combustion chamber. Therefore,
this system recirculates part of emission gas fromthe exhaust port of the cylinder head to the
combustion chamber through the intake manifold
to decrease the air/fuel mixture combustion
temperature, resulting in reduction of NOx.
The EGR flow rate is controlled by the EGR valve
so as not to decrease the driveability.
OPERATION
The EGR valve is being closed and does not
recirculate exhaust gases under one of the following
conditions. Otherwise, the EGR valve is opened
and recirculates exhaust gases.DThe engine coolant temperature is low.
DThe engine is at idle.
DThe throttle valve is widely opened.
SYSTEM DIAGRAM
ON Throttle body
EGR control
solenoid valve
Engine
control
relay
Battery EGR valve
Crank angle sensor
Throttle position sensor Engine-ECU
Engine coolant
temperature sensor Air flow sensor

ENGINE AND EMISSION CONTROL -Emission Control System
EGR control solenoid valve
Vacuum tank
Alternator
EGR valve
Throttle body
17-14
COMPONENT LOCATION
EXHAUST GAS RECIRCULATION (EGR)
CONTROL SYSTEM CHECK
1. Disconnect the vacuum hose (green stripe) from the EGR
control solenoid valve, and then connect a hand vacuum
pump via the three-way terminal.
2. When the engine is hot or cold, check the condition of
vacuum by racing the engine.
When engine is cold
(Engine coolant temperature: 20_C or less)
Throttle valveNormal vacuum condition
Open quicklyNo vacuum will generate
(the same as barometric pressure.)
When engine is hot
(Engine coolant temperature: 80_C or higher)
Throttle valveNormal vacuum condition
Open quicklyIt will momentarily rise over 13 kPa
3. Disconnect the three-way terminal.
4. Connect the hand vacuum pump to the vacuum hose
(green stripe).
5. Check whether the engine stalls or the idling is unstable
when a vacuum of 27 kPa or higher is applied during
idling.
Three-way
terminal
EGR control
solenoid valveVacuum
tankAlternator
EGR control
solenoid valveVacuum
tank
Alternator
Green stripe