1991 MITSUBISHI ECLIPSE engine

24-24 HEATERS AND AIR CONDITIONING - Service Adjustment Procedures
COMPRESSOR NOISENUFIABWhen investigating an air conditioning related noise, you must
first know the conditions when the noise occurs. These
conditions are: weather, vehicle speed, in gear or neutral,
engine temperature or any other special conditions.
Noises that develop during air conditioning operation can oftenbe misleading. For example: what sounds like a failed front
bearing or connecting rod, may be caused by loose bolts, nuts,mounting brackets, or a loose clutch assembly. Verify acces-
sory drive belt tension (power steering, or alternator).
Improper accessory drive belt tension can cause a misleading
noise when the compressor is engaged and little or no noise
when the compressor is disengaged.
Drive belts are speed sensitive. That is, at different engine
speeds, and depending upon belt tension, belts can develop
unusual noises that are often mistaken for mechanical prob-
lems within the compressor.
Adjustment Procedures
(1) Select a quiet area for testing. Duplicate conditions as
much as possible. Switch compressor on and off several
times to clearly identify compressor noise.
To duplicate high ambient conditions (high head pressure),restrict air flow through condenser. Install manifold gauge
set to make sure discharge pressure doesn’t exceed 2,070
kPa (300 psi).
(2) Tighten all compressor mounting bolts, clutch mounting
bolt, and compressor drive belt. Check to assure clutch coilis tight (no rotation or wobble).
(3) Check refrigerant hoses for rubbing or interference that cancause unusual noises.
(4) Check refrigerant charge (See “Charging the System”).
(5) Recheck compressor noise as in Step 1.
(6) If noise still exists, loosen compressor mounting bolts and
retorque. Repeat Step 1.
(7) If noise continues, replace compressor and repeat Step 1.
Condenser fan motor relay,
Magnet clutch
relay, Blower
motor High
relayHeater relayML0312
16W908
POWER RELAY CHECKNUFNAE
NOTEFor information concerning the installation position of each
relay, refer to
P.24-8.CONDENSER FAN MOTOR RELAY, MAGNET CLUTCH
RELAY, BLOWER MOTOR HIGH RELAY, HEATER RELAY
Check for continuity between the terminals when- the battery
power-supply is applied to terminal (2). and terminal (4) is
grounded.
1 When current flows 1 Between terminals l-3 1 Continuity1
I
When no currentBetween terminals l-3 No continuity
flowsBetween terminals 2-4 Continuity
IKinks in the refrigerant tubing or sharp bends in the
Never attempt to rebend formed lines to fit. Use the
refrigerant hose lines will greatly reduce the
capac-correct line for the installation you are servicing.
ity of the entire system. High pressures are
pro-A good rule for the flexible hose lines is keep the
duced in the system when it is operating. Extreme
radius of all bends at least 10 times the diameter of
care must be exercised to make sure that all
the hose.
connections are pressure tight. Dirt and moisture
Sharper bends will reduce the flow of refrigerant.
can enter the system when it is opened for repair or
The flexible hose lines should be routed so that theyreplacement of lines or components. The following
are at least 80 mm (3 in.) from the exhaust manifold.precautions must be observed.
It is good practice to inspect all flexible hose lines atThe system must be completely discharged before
least once a year to make sure they are in good
opening any fitting of connection in the refrigeration
condition and properly routed.
Fsystem. Open fittings with caution even after the
Unified plumbing connections with O-rings. These
4’system has been discharged. If any pressure is
noticed as a fitting is loosened, allow trappedO-rings are not reusable.
pressure to bleed off very slowly.

HEATERS AND AIR CONDITIONING - Service Adjustment Procedures 24-25
16A1077
20AO499
CONDENSER FAN MOTOR HIGH-LOW SELECTING RELAYCheck for continuity between the
term,inals when the battery
power-supply is applied to terminal
(5), and terminal (3) is
grounded.
IWhen current flows1 Between terminals l-2 1 Continuity1When no current
flows
IDLE-UP OPERATION CHECKN24FoAA
(I) Before inspection and adjustment set vehicle in the
following condition:
l Engine coolant temperature:
80-90°C (176-194°F)
lLights, electric cooling fan and accessories: Set to OFFl Transaxle: Neutral
(N or P for vehicles with A/T)l Steering wheel: Straightforward
(2) Check whether or not the idling speed is the standard
value.Standard value:
4.8L Engine>700 rpm
<2.0L DOHC Engine>750 rpm
NOTE
There is no necessity to make an adjustment, because theidling speed is automatically adjusted by the
ISC” system.
If, however, there occurs a deviation from the standard
value for some reason, check the
ISC” system.
(3) Check to be sure that the idlig speed becomes the standardvalue when the air conditioner switch is switched ON and
the air conditioner is activated.
Standard value: 850 rpm
NOTE
There is no necessity to make an adjustment, because theidling speed is automatically adjusted by the
ISC” system.
If, however, there occurs a deviation from the standard
value for some reason, check the
ISC” system.
ISC: Idle Speed Control

HEATERS AND AIR CONDITIONING - Heater Unit24-31
HEATER UNIT
REMOVAL AND INSTALLATIONN24m-
Pre-removal OperationeDraining of Engine Coolant(Refer to GROUP 7-Service Adjust-ment Procedures.)
@Removal of Floor Console and In-
strument Panel
(Refer to GROUP 23-Floor Consoleand Instrument Panel.)Post-installation Operation
*Supplying of Coolant
(Refer to GROUP 7-Service Adjust-ment Procedures.)
l installation of Floor Console and
Instrument Panel
(Refer to GROUP 23-Floor Consoleand Instrument Panel.)


shower duct>
Jshower duct>
Removal steps
1. Center reinforcement
2. Shower duct (R.H.)
3. Distribution foot duct
;: ;Z;;er duct assembly
:z6. Evaporator
7. Heater unit
8. Lap cooler duct (A)
NOTE(1) Reverse the removal procedures to reinstall.(2) 4* : Refer to “Service Points of Removal”.

HEATERS AND AIR CONDITIONING - ComDressor24-37
COMPRESSOR <7.8L Engine>
em REMOVAL AND INSTALLATION
F)
*Removal of the distributor CapPost-installation Operation
@Charging of Refrigerant
(Refer to P.24-21.)@Adjustment of Compressor DriveBelt (Refer to P.24-23.)*Checking for Gas Leakage(Refer to P.24-15.)*Performance Test(Refer to P.24-16.)Removal steps of compressor drive belt and
tension pulley
l *1, Compressor drive belt2. Tension pulley assembly installation bolt
3. Tension pulley assembly4. Bolt
5. Tension pulley6. Bolt
7. Adjustment plate
8. Tension pulley bracket2
13-15
ft.lbs.45-55 Nm
H 12 11
-10
2OAO456Removal steps of compressor
4*1. Compressor drive belt
9. Magnetic clutch harness connector
+e l * 10. Suction hose connection+e I)+ 11. Discharge hose connectionl a 12. O-rings
+* l + 13. Compressor14. Compressor bracket
NOTE(1) Reverse the removal procedures to reinstall.(2) l * : Refer to “Service Points of Removal”.
(3) W : Refer to “Service Points of Installation”.(4) m : Non-reusable parts.

24-40HEATERS AND AIR CONDITIONING - CompressorCOMPRESSOR
<2.0L DOHC Engine>
REMOVAL AND INSTALLATIONPre-removal OperationaDischarge of Refrigerant
(Refer to
P.24-19.)l Removal of VSV Bracket on theCowl Top <2.0L Turbo>
*Disconnection of High-tension
Cables and Connections for Igni-
tion Coil etc.
*Removal
of Center Bearing
Bracket Mounting Bolt
(Referto GROUP 2-Drive Shaft.)Post-installation Operation
*Installation of VSV Bracket<2.0L Turbo>
*Installation of Center
Bearin!Bracket Mounting Bolt *Adjustment of Compressor Drivt
Belt (Refer to P.24-23.)Kharging of Refrigerant
(Refer to P.24-21.)l ehecking for Gas ‘Leakage(Refer to P.24-15.)l Performance Test(Refer to P.24-16.)
N24SA.-tension pulley
1. Alternator drive belt
4*2. Tension pulley assembly installation boltI)+ 3. Tension pulley assembly~~ 2: Grpressor dnve belt
6. Tension pulley
7. Bolt
8. Adjustment plate
9. Tension pulley bracket23-34
ft.lbs.45-55 Nm
33-39 ft.lbs.
2OAO4.58Removal steps of compressor drive belt andRemoval steps of compressor
1. Alternator drive belt
l *2. Tension pulley assembly installation boltl +3. Tension pulley assemblyl +4. Compressor drive belt10. Magnetic clutch harness connector+* l * 11. Suction hose connectionl + 12. Discharge hose connectionl + 13. O-rings
** l * 14. Compressor15. Compressor bracket
NOTE(I) Reverse the removal procedures to reinstall.(2) +e : Refer to “Service Points of Removal”.
(3) l + : Refer to “Service Points of Installation”.(4) m : Non-reusable parts.

HEATERS AND AIR CONDITIONING - condenser and Condenser Fan Motor24i45CONDENSER AND CONDENSER FAN MOTOR
_--REMOVAL AND INSTALLATIONPre-removal Operation of
Condenserl Discharge of Refrigerant(Refer to P.24-19.)
NZITA-Post-installation Operatior
of Condenser
l charging of Refrigerant(Refer to P.24-21.)*Checking for Gas Leakage(Refer to P.24-15.)@Performance Test(Refer to P.24-16.)Removal of condenser
1. Condenser fan motor connecter
2. Condenser fan motor assembly
3. Radiator fan motor connecter<2.0L.Turbo>
4.
Therm0 sensor connecter <2.0L.Turbo>
4*5. Radiator fan motor assembly<2.0L.Turbo>
6. Upper insulator+e ~~ 7. Discharge pipe connectionl * l +8. Liquid pipe connection
4*9. Condenser
Removal of condenser fan motor
1, Condenser fan motor connecter
2. Condenser fan motor
assembly
NOTE(1) Reverse the removal procedures to reinstall.
(2) +e : Refer to “Service Points of Removal”.(3) l 4 : Refer to “Service Points of Installation”
SERVICE POINTS OF REMOVAL
N24TBAF5. REMOVAL OF RADIATOR FAN MOTOR ASSEMBLY
To remove the radiator fan motor assembly,
)~ll it out,
keeping the radiator lifted.
7. DISCONNECTION OF DISCHARGE PIPE/8. LIQUID
PIPEIf the hoses are disconnected, cap the hoses with a blank
plug to prevent entry of dust, dirt, and water.
9. REMOVAL OF CONDENSER
Move the radiator toward the engine, and then remove the
condenser upward.

HEATERS AND AIR CONDITIONING- Engine Coolant Temperature Switch24-51
ENGINE COOLANT TEMPERATURE SWITCH <2.0L DOHC Engine>
-.REMOVAL AND INSTALLATIONN24xA-
1 to GROUP f-service Adjust-1ment Procedures.)
22-28
ft.lbs.
Removal steps1. Engine coolant temperature switch
connector (2-pin)
.4 2. Engine coolant temperature switch(always-closed type)
NOTE(1) Reverse the removal procedures to reinstall.(2) l 4 : Refer to “Service Points of Installation”.
20A0190I
INSPECTIONN24XcAAENGINE COOLANT TEMPERATURE SWITCH
(ALWAYS-
CLOSED TYPE CHECK)
(1) Remove the engine coolant temperature switch from the
water outlet fitting.
(2) Immerse the engine coolant temperature switch in oil and
heat by a gas stove or similar method so as to increase theoil temperature.
(3) Check to be sure that the engine coolant temperature
switch is switched OFF when the oil temperature reaches
the standard value.
Standard value:
112- 118°C (233-244°F)
CautionUse engine oil for this test; stir it well while heating,
and do not heat more than necessary.
SERVICE POINTS OF INSTALLATIONN24XDM2. INSTALLATION OF ENGINE COOLANT TEMPERATURE
SWITCH (ALWAYS-CLOSED TYPE)
Apply a coating of the specified sealant to the threaded
parts and then install the engine coolant temperature
switches.
Specified sealant: MOPAR Part No.4318034 or ewiva-lent

.^
EMISSION CONTROL
SYSTEMS
CONTENTSN25AA-
CATALYTICCONVERTER...............................20CRANKCASE EMISSION CONTROL
SYSTEM...........................................................7Components Location
...................................7Crankcase Ventilation System
Inspection......................................................8Positive Crankcase Ventilation Valve
...........8EVAPORATIVE EMISSION CONTROL
SYSTEM...........................................................9
AirConditionerSwitch.................................14Air Flow Sensor, Engine Coolant
Temperature Sensor and Intake Air
Temperature Sensor
.....................................14
Canister.........................................................14Components Location
...................................9
FuelFillerCapInspection............................14Overfill Limiter (Two-way Valve)
..................14
PurgeControlSolenoidValve......................13Purge Control
SystemInspection................11
PurgeControlValve.....................13EXHAUST GAS RECIRCULATION (EGR)
SYSTEM...........................................................15Air-fuel Ratio Control (MPI) System
............20Components Location
...................................15EGR Control Solenoid Valve

.................................................19
EGR
SystemInspection...............................17EGR Temperature Sensor
......19
EGR Valve.....................................................18
Therm0 Valve 2.0L DOHC Engine>...................................18
SPECIFICATIONS.............................................2General Specifications
..................................2
Sealant..........................................................2Service Specifications
...................................2
TorqueSpecifications...................................2
TROUBLESHOOTING......................................3
VACUUMHOSES...........................................4
VacuumHosesRouting...............................4