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:
TESTING CRANK ANGLE SENSOR CIRCUIT - G - TESTS W/CODES article in the
ENGINE PERFORMANCE section.
On Eclipse and Laser, see NS-4A: REPAIRING CRANK ANGLE SENSOR
in G - TESTS W/CODES - 1.8L article.
On Ram-50, Stealth, Pickup and 3000GT testing information not
available at time of publication.
DISTRIBUTORLESS IGNITION SYSTEM (DIS)
Ignition Coil Resistance (4-Cyl Vehicles Except Eclipse 2.0L)
1) Using a Digital Volt/Ohmmeter (DVOM), measure primary coi\
l
resistance between ignition coil connector terminals No. 2 and No. 3
(coils for cylinders No. 1 and No. 4) and terminals No. 1 and No. 3
(coils for cylinders No. 2 and No. 3). See Fig. 2.
Fig. 2: Testing Ignition Coil Primary Resistance (4-Cylinder)
Courtesy of Mitsubishi Motor Sales of America.
2) Measure secondary coil resistance between coil towers for
cylinders No. 1 and No. 4 and between coil towers for cylinders No. 2
and No. 3. See Fig. 3. Primary and secondary coil resistance should be
within specification. See DIS IGNITION COIL RESISTANCE table.
Fig. 3: Testing Ignition Coil Secondary Resistance (4-Cylinder)
Courtesy of Mitsubishi Motor Sales of America.
Ignition Coil Resistance (Eclipse 2.0L)
1) Using a DVOM, measure primary coil resistance between
ignition coil connector terminals No. 2 and No. 4 (coils for cylinders
No. 1 and No. 4) and between terminals No. 4 and No. 1 (coils for
cylinders No. 2 and No. 3). See Fig. 2.
2) Measure secondary coil resistance between coil towers for
cylinders No. 1 and No. 4 and between coil towers for cylinders No. 2
and No. 3. See Fig. 3. Primary and secondary coil resistance should be
within specification. See DIS IGNITION COIL RESISTANCE table.
DIS IGNITION COIL RESISTANCE TABLE Ohms @ 68
F (20C) \
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Application Primary Secondary
All Models ........... .77-.95 .......... 10.3-13.9
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Power Transistor (Eclipse)
1) Disconnect power transistor connector. Using an analog
ohmmeter, connect positive ohmmeter lead to terminal No. 7 and
negative lead to terminal No. 3. See Fig. 4. Ensure there is no
continuity.
Fig. 4: Power Transistor Connector ID (Eclipse)
Courtesy of Mitsubishi Motor Sales of America.
2) Using a 1.5-volt dry cell battery, connect positive end of
1.5-volt battery to power transistor terminal No. 6 and negative end
to terminal No. 3. Ohmmeter should now read continuity between power
transistor terminals No. 7 and No. 3.
3) Connect positive end of 1.5-volt battery to power
transistor terminal No. 2 and negative end to terminal No. 3. Connect
positive ohmmeter lead to terminal No. 1 and negative lead to terminal
No. 3. Ohmmeter should read continuity. Replace power transistor if it
does not test as described.
Power Transistor (Colt Vista, Galant, Montero, Pickup &
Ram-50)
1) Disconnect power transistor connectors. Using a DVOM,
connect positive ohmmeter lead to terminal No. 2 and negative lead to
terminal No. 3. See Fig. 5. Ensure there is no continuity.
(2) Analog Ohmmeter (2) With 1.5 V Battery
Cylinders Connected Between Connected Between
Tested Terminals (No 1.5 V Battery) Terminals\
1 & 4 ......... 3 & 7 No Continuity ....... 6 & 7 Continuity
2 & 5 ......... 2 & 7 No Continuity ....... 5 & 7 Continuity
3 & 6 ......... 1 & 7 No Continuity ....... 4 & 7 Continuity
(1) - All tests performed with power transistor disconnected. Replace
power transistor if it does not test as described.
(2) - See Fig. 8 for terminal identification.
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MAGNETIC & OPTICAL IGNITION
Ignition Coil Resistance
1) Using a DVOM, measure primary coil resistance between
positive and negative terminals of coil. See Fig. 9. For ignition coil
terminal identification See Fig. 11 - 13.
2) Measure secondary coil resistance between coil positive
terminal and ignition coil tower. See Fig. 10.
3) Primary and secondary coil resistance should be within
specification. See IGNITION COIL RESISTANCE table.
Fig. 9: Testing Ignition Coil Primary Resistance (6-Cylinder)
Courtesy of Mitsubishi Motor Sales of America.
Fig. 10: Testing Ignition Coil Secondary Resistance (6-Cylinder)
Courtesy of Mitsubishi Motor Sales of America.
Fig. 11: Ign Coil Term ID (Colt, Eclipse, Mirage 1.5L, P/U & Ram 50
2.4L)
Courtesy of Mitsubishi Motor Sales of America.