Mitsubishi 380. Manual — part 352

EMISSION CONTROL

ENGINE AND EMISSION CONTROL

17-76

EMISSION CONTROL

GENERAL DESCRIPTION

M1173000100314

The emission control system consists of the fol-

lowing subsystems:

• Positive crankcase ventilation system

• Evaporative emission system

• Exhaust emission control system

DIAGNOSIS

M1173000700112

SPECIAL TOOLS

M1173000600193

SYMPTOM

PROBABLE CAUSE

REMEDY

Engine will not start or hard
to start

Vacuum hose disconnected or damaged

Repair or replace

Malfunction of the evaporative emission
purge solenoid

Repair or replace

Rough idle or engine stalls

Vacuum hose disconnected or damaged. Repair or replace

Malfunction of the positive crankcase
ventilation valve

Replace

Malfunction of the purge control system

Check the system; If there is a
problem, check its component
parts.

Excessive oil consumption

Positive crankcase ventilation line
clogged

Check positive crankcase
ventilation system

TOOL

TOOL NUMBER AND
NAME

SUPERSESSION

APPLICATION

MB995061
Purge flow indicator

MLR6890A
Part of MIT280220

Inspection of purge
control system

MD998770
Oxygen sensor wrench

MD998770-01 or General
service tool

Removal/installation of
heated oxygen sensor

EMISSION CONTROL

ENGINE AND EMISSION CONTROL

17-77

VACUUM HOSES

VACUUM HOSE ROUTING

M1173000900398

AK301810

EVAPORATIVE EMISSION

VENTILATION SOLENOID

INTAKE MANIFOLD

PLENUM

CHAMBER

THROTTLE

BODY

FRONT

TO EVAPORATIVE EMISSION

CANISTER

EMISSION CONTROL

ENGINE AND EMISSION CONTROL

17-78

VACUUM CIRCUIT DIAGRAM

M1173007100252

VACUUM HOSE INSTALLATION

M1173007200129

1. When connecting the vacuum hoses, they should be

securely inserted onto the nipples.

2. Connect the hoses correctly, using the VACUUM HOSE

ROUTING diagram as a guide.

07DB110A

B: BLACK

THROTTLE BODY

INTAKE MANIFOLD

FROM

AIRCLEANER

TO

COMBUSTION

CHAMBER

EVAPORATIVE EMISSION

PURGESOLENOID

(ON: OPEN)

EVAPORATIVE EMISSION

CANISTER

FUEL

TANK

B

B

B

CHAMBER

EMISSION CONTROL

ENGINE AND EMISSION CONTROL

17-79

VACUUM HOSE CHECK

M1173007300171

1. Using the VACUUM HOSE ROUTING diagram as a guide,

check that the vacuum hoses are correctly connected.

2. Check the connection of the vacuum hoses, (removed,

loose, etc.) and confirm that there are no sharp bends or
damage.

POSITIVE CRANKCASE VENTILATION SYSTEM

GENERAL DESCRIPTION (POSITIVE CRANKCASE VENTILATION SYSTEM)

M1173005000293

The positive crankcase ventilation (PCV) system pre-
vents the escape of blow-by gases from inside the
crankcase into the atmosphere.
Fresh air is sent from the air cleaner into the crank-
case through the breather hose to be mixed with the
blow-by gas inside the crankcase.
The blow-by gas inside the crankcase is drawn into
the intake manifold through the PCV valve.

The PCV valve is designed to lift the plunger accord-
ing 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 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

07DB111A

POSITIVE CRANKCASE

VENTILATION VALVE

VENTILATION HOSE

BREATHER HOSE