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A/C S YSTE M P R EC AU TIO NS
1991 M it s u bis h i M onte ro
AIR CONDITIONING & HEAT
A/C System Precautions
* PLEASE READ THIS FIRST *
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
BEFORE OPENING THE SYSTEM
Before disconnecting any lines or fittings, the system must
be completely discharged using approved refrigerant recovery/recycling
equipment.
DISCHARGING A/C SYSTEM
NOTE: Recent findings by the EPA indicate that R-11, R-12 and R-113
are harmful to the Earths' protective Ozone layer. Make every
attempt possible, to avoid discharging R-11, R-12 or R-113
into the atmosphere.
1) Remove service valve caps and install gauges. For high
side gauge hose, Adapter (D81L-19703-A) must be used to connect to
high side service valve.
2) Place open end of center hose in garage exhaust outlet or
in a well ventilated area. Slightly open low side gauge valve and let
refrigerant escape slowly without loosing refrigerant oil.
3) When system is nearly discharged, using approved
refrigerant recovery/recycling equipment, open high side gauge valve
to release any pressure trapped in compressor. Close valves
immediately after discharging to prevent entry of moisture.
DISCONNECTING LINES & FITTINGS
1) After system is discharged, using approved refrigerant
recovery/recycling equipment, carefully clean entire area around
coupling nut to prevent dirt entering system. Always use two wrenches
to avoid twisting or distorting lines and fittings (hold fitting with
one wrench while loosening coupling nut with second wrench).
2) Cap or plug all LINES and FITTINGS immediately to prevent
entry of air and moisture into system. Do not remove these caps until
connections are being made.
COMPONENT REPLACEMENT
When components are replaced, system oil level must be
adjusted. Add refrigeration oil to replacement component. See
Compressor oil Check article, as well as, Component Oil Replacement
Quantities" chart under "A/C SYSTEM SPECS" article in this section.
USING R-12 REFRIGERANT - SAFETY PRECAUTIONS
1) Always work in a well-ventilated, clean area. Refrigerant
(R-12) is heavier than oxygen, and will displace oxygen in a confined
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D - A D JU STM EN TS
1991 M it s u bis h i M onte ro
1991 ENGINE PERFORMANCE
On-Vehicle Adjustments
Chrysler Motors: Colt, Colt 200, Colt Vista,
Ram-50, Stealth, Summit
Mitsubishi: Eclipse, Galant, Mirage, Montero,
Pickup, 3000GT
ENGINE MECHANICAL
Before performing any on-vehicle adjustments to fuel or
ignition system, ensure engine mechanical condition is okay.
VALVE CLEARANCE
NOTE: All engines except 1.5L use hydraulic valve lifters. Valve
adjustment is only required on 1.5L engines. To check
hydraulic valve lifter operation, see CHECKING HYDRAULIC
VALVE LIFTERS.
MECHANICAL VALVE LIFTERS
CAUTION: DO NOT rotate crankshaft in opposite direction of normal
engine rotation.
1.5L
1) Ensure engine is at normal operating temperature. Remove
all spark plugs and valve cover. Rotate crankshaft to position
cylinder No. 1 on TDC of compression stroke. Adjust intake valves on
cylinders No. 1 and No. 2, and exhaust valves on cylinders No. 1 and
No. 3. See VALVE CLEARANCE ADJUSTMENT table for specification.
2) Rotate crankshaft 360 degrees to position cylinder No. 4
on TDC of compression stroke. Adjust intake valves on cylinders No. 3
and No. 4, and exhaust valves on cylinders No. 2 and No. 4.
VALVE CLEARANCE ADJUSTMENT TABLE
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Cold Hot
Application In. (mm) In. (mm)
Intake ............ .003 (.07) ......... .006 (.15)
Exhaust ........... .007 (.17) ......... .010 (.25)
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CHECKING HYDRAULIC VALVE LIFTERS
Except 1.5L
1) Remove valve cover. Push downward on end of rocker arm
above lash adjuster. If lash adjuster is normal, it will feel hard. If
lash adjuster moves downward easily when pushed, replace adjuster.
2) If lash adjuster feels soft or spongy, oil with air has
probably entered lash adjuster. If this occurs, check engine oil
level. If engine oil level is okay, check oil screen and oil screen
gasket for damage.
3) After repairing cause of air leak, warm engine to
operating temperature. Drive vehicle at low speed for approximately 5
minutes. Turn engine off for a few minutes.
4) Restart engine and drive at low speed for approximately 5
minutes. Repeat this step several times for about one hour. This helps
remove air from engine oil.
IGNITION TIMING
NOTE: Perform all adjustments with engine at normal operating
temperature, cooling fan and accessories off, transmission
in Park or Neutral, and front wheels in straight-ahead
position. Set curb idle speed to specification. See IDLE
SPEED SPECIFICATIONS table under IDLE SPEED & MIXTURE.
IGNITION TIMING
1) Locate ignition timing adjustment connector. See IGNITION
TIMING ADJUSTMENT CONNECTOR LOCATION table. Connect jumper wire
between ignition timing adjustment connector and ground. Check
ignition basic timing.
2) If ignition basic timing is not within specification,
loosen distributor (or crank angle sensor on engines with dual coil
assembly) and rotate to adjust timing if necessary. See IGNITION
TIMING SPECIFICATIONS table. Disconnect jumper wire from ignition
timing adjustment connector.
IGNITION TIMING SPECIFICATIONS TABLE (Degrees BTDC@RPM)
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Application (1) Basic (1) (2) Actual
1.5L
Colt, Colt 200
Mirage & Summit ....... 5@650-850 ........ 10@650-850
1.6L
Mirage ................. 5@650-850 ......... 8@650-850
1.8L
Eclipse ................ 5@600-800 ........ 10@600-800
2.0L
Colt Vista &
Galant (VIN V) ........ 5@600-800 ........ 10@600-800
Eclipse ................ 5@650-850 ......... 8@650-850
Galant
(VIN R) ............... 5@650-850 ......... 8@650-850
(VIN U) ............... 5@650-850 ........ 12@650-850
2.4L
Pickup & Ram-50 ........ 5@650-850 ......... 8@650-850
3.0L
Montero, Pickup, Ram-50
Stealth & 3000GT ...... 5@600-800 ........ 15@600-800
(1) - Transmission in Park or Neutral.
(2) - Actual timing may fluctuate.
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IGNITION TIMING ADJUSTMENT CONNECTOR LOCATION TABLE \
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Application (1)(2) Wire Color Locati\
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Colt, Colt Vista, Colt 200,
Mirage & Summit
1.5L, 1.6L & 2.0L ................ Yellow/Red ............. (3)\
Eclipse
1.8L & 2.0L (Except Turbo) ........ Yellow/Red ............. (4\
)
2.0L Turbo ....................... Yellow/Black ............ (4)\
Galant
exists in wire between alternator terminal "S" and positive battery
terminal or fusible link is blown.
4) Start engine. Ensure all lights and accessories are off.
Operate engine at 2500 RPM and read voltmeter when alternator output
current drops to 10 amps or less. Voltage regulator is okay if voltage
output is within specification. See REGULATOR VOLTAGE SPECIFICATIONS
table.
BENCH TESTING
RECTIFIER ASSEMBLY
1) Using ohmmeter, check for continuity between both diodes
and stator coil lead connection. See Fig. 11. Reverse leads. If
continuity exists in both directions, diode is shorted. Replace
rectifier assembly.
2) To check entire diode assembly, use an ohmmeter to check
for continuity between both ends of each diode. See Fig. 11. Switch
ohmmeter leads. Continuity should exist in one direction, but not
other. If no continuity exists or continuity exists in both
directions, diode is defective. Replace rectifier assembly.
Fig. 11: Testing Rectifier Assembly
Courtesy of Mitsubishi Motor Sales of America.
ROTOR
1) Check continuity across rotor slip rings. Resistance
should be within specification. See ROTOR RESISTANCE SPECIFICATIONS
table. Replace rotor if no continuity exists or resistance is not
within specification.
2) Check continuity between individual slip rings and rotor
shaft. If continuity exists, rotor coil or slip ring is grounded.
Replace rotor.
STATOR
Ensure no continuity exists between stator coil leads and
stator core. Check continuity between leads of stator coil. If no
continuity exists between coil leads, replace stator.
OVERHAUL
Replace brushes if worn to limit line. Limit line is line
closest to rotor contact end of brush. Brushes can be retained in
brush holder while installing rotor by inserting wire into back of
rear housing.
Fig. 12: Exploded View of Typical Mitsubishi Alternator
Courtesy of Mitsubishi Motor Sales of America.
SPECIFICATIONS
ALTERNATOR MINIMUM OUTPUT SPECIFICATIONS TABLE \
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Application Amps
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F - B ASIC T E STIN G
1991 M it s u bis h i M onte ro
1991 ENGINE PERFORMANCE
Basic Diagnostic Procedures
Chrysler; Colt, Colt 200, Colt Vista, Ram-50, Stealth,
Summit
Mitsubishi; Eclipse, Galant, Mirage, Montero, Pickup, 3000GT
INTRODUCTION
The following diagnostic steps will help prevent overlooking
a simple problem. This is also where to begin diagnosis for a no start
condition. First step in diagnosing any driveability problem is
verifying customer's complaint with a test drive under conditions
problem reportedly occurred.
Before entering self-diagnostics, perform a careful and
complete visual inspection. Most engine control problems result from
mechanical breakdowns, poor electrical connections or
damaged/misrouted vacuum hoses. Before condemning computerized system,
perform each test listed in article.
NOTE: Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM)\
with a minimum 10-megohm input impedance, unless stated
otherwise in test procedure.
PRELIMINARY INSPECTION & ADJUSTMENTS
VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed,
stretched, cut or pinched wiring. Ensure electrical connectors fit
tightly and are not corroded. Ensure distributor cap and rotor are
free of cracks, carbon trails or contamination. Ensure vacuum hoses
are properly routed and not pinched or cut. See M - VACUUM DIAGRAMS
article in the ENGINE PERFORMANCE Section to verify routing and
connections (if necessary). Inspect air induction system for possible
vacuum leaks.
MECHANICAL INSPECTION
Compression
Check engine mechanical condition with a compression gauge,
vacuum gauge, or an engine analyzer. See engine analyzer manual for
specific instructions.
WARNING: DO NOT use ignition switch during compression tests. Use a
remote starter to crank engine. Fuel injectors on many models
are triggered by ignition switch during cranking mode, which
can create a fire hazard or contaminate engine's oiling
system.
COMPRESSION SPECIFICATIONS TABLE (1)
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Application Specification
psi (kg/cm)
1.5L (VIN X) .............................. 137 (9.6)
1.6L (VIN Y) ............................. 171 (12.0)
1.8L (VIN T) .............................. 131 (9.2)
pump. If fuel pressure drops slowly, fuel injector is leaking or fuel
pressure regulator valve seat is leaking. Check for faulty fuel
injector or fuel pressure regulator. Repair as required.
11) When fuel pressure test is complete, repeat fuel pressure
release procedure in steps 1) and 2) before disconnecting fuel
pressure gauge. Install new "O" ring at end of high pressure hose.
Check for fuel leaks.
FUEL PUMP TEST TERMINAL LOCATION TABLE
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Application Wire Color Location
Colt, Colt 200 ......... BLK/WHT .............. Center Of Firewall
Colt Vista ............. BLK/WHT ........ Right Center Of Firewall
Eclipse ................ BLK/WHT .......... Rear Of Battery Compt.
Galant ................. YEL/GRN ........... Left Rear Eng. Compt.
Mirage 1.5L ............ BLK/WHT .............. Center Of Firewall
Mirage 1.6L ............ BLK/BLU .............. Center Of Firewall
Montero .................. WHT .......... Right Center Of Firewall
Pickup ................. BLK/BLU ....... Right Side Of Eng. Compt.
Precis ................... YEL ............. Left Rear Eng. Compt.
Summit ................. BLK/WHT .............. Center Of Firewall
Ram-50 ................. BLK/BLU ....... Right Side Of Eng. Compt.
Stealth, 3000GT ........ BLK/BLU .......... Rear Of Battery Compt.
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REGULATED FUEL PRESSURE TABLE \
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At Idle At Idle
w/Vacuum w/o Vacuum
Application psi (kg/cm
) psi (kg/cm)
Non-Turbo .................. 38 (2.7) ....... 47-50 (3.3-3.5)
Turbo
Except Eclipse A/T ....... 27 (1.9) ....... 36-38 (2.5-2.7)
Eclipse A/T .............. 33 (2.3) ....... 36-38 (2.9-3.2)
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Control Relay
Multipurpose relay switches power to vehicle sensors and
actuators including airflow sensor, crank angle sensor, idle speed
control, injectors and fuel pump. When ignition switch is turned to ON
position, ECU energizes coils controlling injectors, airflow sensor
and idle speed control. When ignition switch is turned to START
position, ECU energizes coils (through inhibitor switch on A/T models)\
to supply power to fuel pump. Relay failure will cause a no-start
condition. For testing procedure, see SYSTEM & COMPONENT TESTING
article.
IGNITION CHECKS
SPARK
Check for spark at coil wire (if applicable) and at each
spark plug wire using a high output spark tester. Check spark plug
wire resistance on suspect wires. For wire resistance specification,
see C - SPECIFICATIONS article in the ENGINE PERFORMANCE Section.
CRANK ANGLE SENSOR
For crank angle sensor testing procedure on all models except
Ram-50, Stealth, Eclipse, Laser, Pickup and 3000GT, see TEST NS-5:
Removal
1) Raise and support vehicle. Remove front wheel(s). Separat\
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rubber flex hose from hydraulic line at brake hose mount, located on
strut housing. Secure end of hydraulic line to prevent spillage of
brake fluid.
2) Remove hose clip from brake hose mount. Disconnect brake
hose from caliper. Remove upper and lower caliper-to-steering knuckle
bolts. Lift caliper body upward. Remove caliper.
Installation
To install, reverse removal procedure. Tighten bolts to
specification. See the TORQUE SPECIFICATIONS table. Bleed brake
system. See BLEEDING BRAKE SYSTEM .
FRONT BRAKE ROTOR
Removal (Montero, Pickup 4WD & Ram-50 4WD)
Raise and support vehicle. Remove and support brake calipers.
Place hub in free-wheeling position. Remove drive hub cover using an
oil filter wrench and protective cloth. Remove snap ring, shim and
free-wheeling hub from drive axle. See Fig. 7. Remove lock washer.
Remove lock nut using Lock Nut Wrench (MB990954). Remove front hub
assembly.
Fig. 7: Exploded View of Front Brake Assembly (4WD)
Courtesy of Mitsubishi Motor Sales of America.
Installation
1) Install front hub assembly. Install and tighten lock nut
to 94-145 ft. lbs. (127-197 N.m), and then loosen and retighten to 18
ft. lbs. (24 N.m). Loosen lock nut 30-40 degrees. Reverse removal
procedure for remaining components. After installation is complete,
check drive axle end play. Adjust end play if not .002" (.05 mm) or
less. Rotate drive axle forward and rearward until maximum end play is
obtained.
2) If adjusting axle shaft end play, use proper shim to
obtain desired end play. Shim is located behind snap ring on end of
drive axle. Install shim, and recheck axle end play.
Removal (Pickup 2WD & Ram-50 2WD)
Raise and support vehicle. Remove front caliper. Remove hub
(dust) cap, cotter pin and nut. Remove washer and outer wheel bearing.\
Remove front hub assembly. Remove bolts attaching rotor to front hub,
and separate assemblies.