1991 MITSUBISHI ECLIPSE engine coolant

HEATERS AND AIR CONDITIONING - Specifications/Troubleshooting24-3LUBRICANTS
u24as-
;xiItemsSpecified lubricantsQuantity
Each connection of refrigerant lineDENS0 OIL 6 or
SUNISO 5GSAs required
Shaft seal of the compressor
SEALANT AND ADHESIVES, Items
Engine coolant temperature switch threaded partSpecified sealant and adhesive
MOPAR Part No.4318034 or equivalentN24CE-
TROUBLESHOOTINGN24EBAQ
SymptomHeater insufficient heat
No ventilation even when
mode selection knob is
operatedBlower motor inoperative
Probable causeObstructed heater outlets
Blend air dampers improperly adjusted or bindingThermostat malfunction
Obstructed heater hoses
Improperly adjusted control cables
Plugged or partially plugged heater core
Incorrect adjustment of mode selection dampersIncorrect installation of mode selection control wire
Ducts are incorrectly/incompletely connected, crushed,
bent or clogged.
Poor grounding
Burnt-out fuseMalfunction blower switch
Malfunction resister
Malfunction blower motor
Malfunction heater relay
Remedy
Correct
ReplaceAdjust
Clean or replaceAdjust
Repair or replace
Correct
Replace

24-8HEATERS AND AIR CONDITIONING - Troubleshooting
IARNESSES AND COMPONENTS LAYOUT DIAGRAM
1. Air conditioner switch
2. Air conditioner control unit
3. Air-inlet sensor
4.
Air-therm0 sensor
36AOO51
NameSymbolAir conditioner control unit
DAir conditioner switch
GAir inlet sensor
FAir
therm0 sensorFBlower motor High relay
E
IrrIor:enser fan motor High-Low selecting
C
NameCondenser fan motor relay
Dual pressure switch
Engine coolant temperature switch
<2.0L DOHC Engine>
Heater relay
Magnetic clutch relay
Symbol
C
BA
H
C
NOTEThe “Name” column is arranged in alphabetical order.
q \
q ---

HEATERS AND AIR CONDITIONING - Service Adjustment Procedures 249*I3
--Air-therm0
sensor
Air inlet
sensor
E>aporator(3)
Set the gauge manifold in place and check whether or not
the pressure at the high-pressure side has become the
dual-pressure switch activation pressure.
(4) Replace the switch if, under ordinary conditions, there is no
continuity.Caution
The condition can be considered to be satisfactory if
there is continuity.
Never increase the pressure in a deliberate attempt to
obtain an abnormally high temperature, because to do
so risks blowing the compressor relief valve.AIR-THERM0 SENSOR AND AIR-INLET SENSOR
If frost forms on the surfaces of the evaporator fins, the cause
might be a malfunction of
air-therm0 sensor.
The temperature of the air-flowing from the evaporator’s outlet
is sensed by the thermistor, and the signals conveying this dataare input to the air conditioner control unit, thus switching the
compressor’s clutch ON or OFF.
This functions when the evaporator’s air-flow is low, or the
evaporator’s fins are clogged by dust, etc., or when the amountof refrigerant is insufficient.
These sensors detect the temperature within the passenger
compartment and the temperature at the cooling unit inlet,
thus causing changes of the resistance value, and this data is
provided to the air conditioner control unit as input.
How to Test the Therm0 Sensor and Air-Inlet Sensor
(1) Disconnect the sensor’s connector at the evaporator case,
and by using an ohmmeter, measure the resistance. The
resistance is normal if it is within the range shown in the
figure at the left; if the resistance is not normal, replace.
(2) If the sensor is normal, there is a malfunction of the air
conditioner control unit, and it should be replaced.
Standard value:
Passenger compartment temperature sensor resist-
ance value:
0°C (32°F)4,852+243 (S-2)
15°C (59°F)2,341+234 (S-2)
25°C (77°F)1,500+150 (52)
ENGINE COOLANT TEMPERATURE SWITCH
<2.0L DOHC Engine>
The engine coolant temperature switch is connected in series
with the compressor magnetic clutch power relay.
It disengages the compressor when the temperature of
engine coolant rises above
115°C (239°F).This is designed to prevent engine overheating when cooling
air is not sufficient for the condenser and radiator. If the enginecoolant temperature switch operates to disengage the com-
pressor, check for the condenser and radiator surface condi-
tions, belt tension and engine coolant level and correct, if
necessary.

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- 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

EMISSION CONTROL SYSTEMS- Evaporative Emission Control SYStem25-m
PURGE CONTROL SYSTEM INSPECTION NZ5lBEK
sensor
P+
Engine control unit
IlEM0086(1) Disconnect the vacuum hose (red stripes) from the throttle
body and connect it to a hand vacuum pump.
(2) Plug the nipple from which the vacuum hose is discon-
nected.(3) Under the engine conditions shown below, check by
applying vacuum from a hand vacuum pump.
When engine is cold-engine coolant temperature:
60% (140°F) or less
Engine operating Applying vacuum
>When engine is hot-engine coolant temperature:
70°C (158°F) or higher
Engine operating
condition
Idling3,000 rpm within
three minutes afterstarting engine
3,000 rpm after
three minutes
have elapsedafter starting
engineApplying vacuum
375
mmHg(14.8 in.Hg.1
Try wpMwvacuum375
mmHg(14.8 in.Hg.1
ResultVacuum is maintained
Vacuum leaks
Vacuum will be main-
tained momentarily,
after which it will
leaks.
NOTEThe vacuum will leak
continuously if the
altitude is 2,200
m(7,200 ft.) or higher,or the intake air
temperature is
50°C(122°F) or higher.