Mitsubishi Lancer Evolution IX. Manual — part 357

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-7

VACUUM CIRCUIT DIAGRAM

M1173007100586

AK501843

From

air

cleaner

To

combustion

chamber

Throttle body

B

B

B

W

R

B

B

AB

Inlet manifold

W

R

B

G

Y

L

Fuel
pressure
regulator

EGR valve

EGR control
solenoid valve

Purge control
solenoid valve

Canister

Vacuum hose colour

B: Black
G: Green
L: Light blue
R: Red
W: White
Y: Yellow

Fuel pressure control
solenoid valve

Air by-pass valve

Check valve

Waste gate actuator

Waste gate
solenoid valve

Air cleaner

Y

B

Y

Brown

VACUUM HOSE CHECK

M1173007300193

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

M1173007200141

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.

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-8

CRANKCASE EMISSION CONTROL
SYSTEM

GENERAL INFORMATION (CRANKCASE
EMISSION CONTROL SYSTEM)

M1173005000691

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 crank-
case 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 inlet manifold through the positive crankcase
ventilation (PCV) valve.
The PCV valve lifts the plunger according to the inlet
manifold vacuum so as to regulate the flow of
blow-by gas properly.
In other words, the blow-by gas flow is regulated dur-
ing low load engine operation to maintain engine sta-
bility, while the flow is increased during high load
operation to improve the ventilation performance.

SYSTEM DIAGRAM

AK501845 AB

PCV valve

Ventilation hose

Breather hose

COMPONENT LOCATION (CRANKCASE
EMISSION CONTROL SYSTEM)

M1173007400297

AK304227AB

PCV valve

POSITIVE CRANKCASE VENTILATION
SYSTEM CHECK

M1173001100373

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.

AK300021

PCV valve

AC

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-9

5. Place a finger at the opening of the PCV valve

and check that vacuum of the inlet 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.

POSITIVE CRANKCASE VENTILATION
(PCV) VALVE CHECK

M1173001200336

AK300022

PCV valve

AC

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.

EVAPORATIVE EMISSION CONTROL
SYSTEM

GENERAL INFORMATION (EVAPORATIVE
EMISSION CONTROL SYSTEM)

M1173005100717

The evaporative emission control system prevents
fuel vapors generated in the fuel tank from escaping
into the atmosphere.
Fuel vapors from the fuel tank flow through the fuel
tank pressure control valve and vapor pipe/hose to
be stored temporarily in the canister.
When driving the vehicle, fuel vapors stored in the
canister flow through the purge solenoid and purge
port and go into the inlet manifold to be sent to the
combustion chamber.
When the engine coolant temperature is low or when
the inlet 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 vapor flow to
the inlet manifold.
This does not only insure the driveability when the
engine is cold or running under low load but also sta-
bilize the emission level.

EMISSION CONTROL <MPI>

ENGINE AND EMISSION CONTROL

17-10

SYSTEM DIAGRAM

AK401830AB

Throttle body

Canister

Check valve

From
fuel
tank

OFF

ON

Purge
control
solenoid
valve

Engine
control
relay

Battery

Engine-ECU

Air flow sensor

Engine coolant
temperature sensor

Intake air
temperature sensor

Barometric pressure sensor

COMPONENT LOCATION (EVAPORATIVE
EMISSION CONTROL SYSTEM)

M1173007500302

AK304229AB

Purge control
solenoid valve

PURGE CONTROL SYSTEM CHECK

M1173001400664

AK304230AB

Throttle body

Red stripe

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 negative

pressure of 53 kPa, and check the condition of the
negative pressure.

When engine is cold

(Engine coolant temperature: 40

°C or less)

Engine condition

Normal condition

At idle

Negative pressure is
maintained.

3,000 r/min

When engine is hot

(Engine coolant temperature: 80

°C or higher)

Engine condition

Normal condition

At idle

Negative pressure is
maintained.

3,000 r/min (within 3 minutes
after engine starts)

Negative pressure
will leak.