Mitsubishi Galant. Manual — part 378

EMISSION CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-82

<3.0L ENGINE>

COMPONENT LOCATION

M1173007400026

AKX00334

BREATHER HOSE

VENTILATION HOSE

PCV VALVE

AB

AKX01299 AB

POSITIVE CRANKCASE VENTILATION
(PCV) VALVE
<2.4L ENGINE>

AKX01300AB

POSITIVE CRANKCASE VENTILATION
(PCV) VALVE
<3.0L ENGINE>

EMISSION CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-83

CRANKCASE VENTILATION SYSTEM CHECK

M1173001100049

1. Remove the positive crankcase ventilation (PCV) valve from

the rocker cover, then reconnect the PCV valve to the
vacuum supply hose.

2. With the engine idling, put your finger on the open end of the

PCV valve, and check for negative pressure (vacuum).

NOTE: At this time, the plunger in the PCV valve should
move back and forth as the open end is covered and
uncovered.

3. If negative pressure is not felt, clean or replace the PCV

valve. Inspect he vacuum supply hose and vacuum supply
hose port for restriction or plugged condition.

POSITIVE CRANKCASE VENTILATION (PCV)
VALVE CHECK

M1173001200046

1. Hold the PCV valve with the vacuum side down. Insert a thin

rod, and using light pressure, depress the end of the PCV
valve spring by 5

−

10 mm (0.2

−

0.3 inch). Release

pressure on the rod to see if the PCV valve spring will lift the
rod to its original position.

2. If the rod returns quickly to its original position, the PCV

valve is OK. If the stick does not return quickly. clean or
replace the PCV valve.

EVAPORATIVE EMISSION CONTROL SYSTEM

GENERAL INFORMATION

M1173005100063

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 vapor
pipe/hose to be stored temporarily in the evaporative
emission (EVAP) canister.
When the vehicle is in operation, fuel vapors stored
in the EVAP canister flow through the chamber, the
EVAP purge solenoid, purge port and intake manifold
plenum 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 module brings
the EVAP purge solenoid into the OFF state to shut
off the fuel vapor flow to the intake manifold plenum.
This ensures driveability when the engine is cold or
running under low load and also stabilizes the
emission level.

An EVAP ventilation solenoid is provided between
the EVAP canister and atmosphere to monitor for
OBD-II EVAP leaks. This solenoid is normally OFF.
However, it turns ON when monitoring the OBD-II
EVAP leaks and shuts off the atmosphere flow to the
EVAP canister. Then the fuel tank differential
pressure sensor monitors the fuel vapor pressure to
detect OBD-II EVAP leaks. The fuel vent valve and
the leveling valve prevent fuel from being overfilled.
The fuel vent valve and the leveling valve prevents
fuel leaks just if the vehicle is rolled over in an
accident.
The vent valve releases the air from the fuel tank
through the evaporative emission canister into the
atmosphere when the fuel tank pressure increases
due to refueling, etc. The vent valve and the air filter
supply the atmospheric air to the evaporative
emission canister when the fuel tank pressure
decreases.

AKX00336

PCV VALVE

AB

AKX00337

5 - 10 mm
(0.2 - 0.3 in)

PCV VALVE

VACUUM SIDE

THIN ROD
(VERY
SMOOTH)

AB

EMISSION CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-84

SYSTEM DIAGRAM

COMPONENT LOCATION

M1173007500023

AKX01303

FUEL TANK DIFFERENTIAL
PRESSURE SENSOR

CHAMBER

LIQUID SEPARATOR

EVAP
CANISTER

EVAPORATIVE
EMISSION
PURGE
SOLENOID
ON: OPEN

PCM

BAROMETRIC PRESSURE
SENSOR

INTAKE AIR TEMPERATURE
SENSOR

ENGINE COOLANT
TEMPERATURE SENSOR

VOLUME AIR FLOW SENSOR

FUEL
TANK

MFI RELAY

FUEL VENT
VALVE

FUEL CUT
OFF VALVE

LEVELING VALVE

VENT VALVE

AIR FILTER

EVAPORATIVE EMISSION
VENTILATION SOLENOID
ON: CLOSED

AC

AKX01304 AB

EVAPORATIVE EMISSION PURGE
SOLENOID
<2.4L ENGINE>

AKX01305

EVAP VENTILATION SOLENOID

FUEL TANK

AB

AKX01306

EVAPORATIVE EMISSION PURGE
SOLENOID
<3.0L ENGINE>

AB

EMISSION CONTROL

TSB Revision

ENGINE AND EMISSION CONTROL

17-85

PURGE CONTROL SYSTEM CHECK (PURGE FLOW CHECK)

M1173001400028

Required Special Tool:
MB995061: Purge flow indicator
1. Disconnect the purge hose from the evaporative emission

(EVAP) purge solenoid, and connect the special tool
MB995061 between the EVAP purge solenoid and the purge
hose.

2. Before inspection and adjustment, set the vehicle in the

following conditions:

•

Engine coolant temperature: 80

−

95

°

C

(

176

−

203

°

F)

•

Lights and accessories: OFF

•

Transmission: P range

3. Run the engine at idle for more than four minutes.

4. Check the purge flow volume when the engine is revved

several times.

Standard value: Momentarily 20 cm

3

/sec. (2.5 SCFH)

or more.

AKX00340

INTAKE MANIFOLD

THROTTLE BODY

TO COMBUSTION
CHAMBER

FROM
AIR
CLEANER

OFF

ON

EVAP PURGE SOLENOID
(ON: OPENED)

PURGE
FLOW
INDICATOR
(MB995061)

PURGE HOSE

EVAP CANISTER

AB