1991 MITSUBISHI MONTERO brake

Fig. 7: Brakes, Steering, & Suspension
Fig. 8: Air Conditioning, Heater & Ventilation

that all of the engine control systems are operating as they were
designed to. Therefore, they are not the cause of the driveability
problem.
The following additional items can not be overlooked as possible
causes of a driveability problem.
1. THROTTLE VALVE AREA - Dirt or ice buildup causing rough idle and
stalling.
2. ENGINE IGNITION TIMING - Must be set with timing terminal
grounded.
3. ENGINE VACUUM - Must be normal for your altitude.
4. ENGINE VALVE TIMING - To specifications.
5. ENGINE COMPRESSION - To specifications.
6. ENGINE P.C.V. SYSTEM - Must flow freely.
7. ENGINE EXHAUST SYSTEM - Must be free of any restrictions.
8. POWER BRAKE BOOSTER - No internal vacuum leaks.
9. TORQUE CONVERTER CONDITION - May cause very low power at breakaway
or high speed (Only 1 condition at a time).
10. FUEL CONTAMINATION - High alcohol or water content.
11. FUEL INJECTORS - Rough idle may be caused by injector wiring not
connected to correct injector.
12. ENGINE SECONDARY IGNITION CHECK - Abnormal scope patterns.
13. TECHNICAL SERVICE BULLETINS - Any that apply to vehicle.
14. All air intake piping and vacuum hoses must be in place and
secure. The proper air filter element must be used.
15. FUEL PRESSURE - Must be correct.
Specification: With no vacuum at the regulator:
48 PSI on V6 & non-turbo 4 Cyl. engines
36 PSI on turbo engines
NS-1: TESTING IGNITION CIRCUIT - 1.6L
Fig. 75: Circuit Diagram NS-1 (1.6L)

The following additional items can not be overlooked as
possible causes of a driveability problem.
1. ENGINE IGNITION TIMING - Must be set with timing terminal
grounded.
2. ENGINE VACUUM - Must be normal for your altitude.
3. ENGINE VALVE TIMING - To specifications.
4. ENGINE COMPRESSION - To specifications.
5. ENGINE P.C.V. SYSTEM - Must flow freely.
6. ENGINE EXHAUST SYSTEM - Must be free of any restrictions.
7. POWER BRAKE BOOSTER - No internal vacuum leaks.
8. TORQUE CONVERTER CONDITION - May cause very low power at breakaway
or high speed (Only 1 condition at a time).
9. FUEL CONTAMINATION - High alcohol or water content.
10. FUEL INJECTORS - Rough idle may be caused by injector wiring not
connected to correct injector.
11. ENGINE SECONDARY IGNITION CHECK - Abnormal scope patterns.
12. TECHNICAL SERVICE BULLETINS - Any that apply to vehicle.
13. All air intake piping and vacuum hoses must be in place and
secure. The proper air filter element must be used.
14. FUEL PRESSURE - Must be correct.
Specification: With no vacuum at the regulator:
48 PSI on V6 & non-turbo 4 Cyl. engines
36 PSI on turbo engines
NS-VER: NO START VERIFICATION PROCEDURE - 1.6L
Fig. 168: Flow Chart NS-VER (1.6L)
DR-VER: DRIVEABILITY VERIFICATION PROCEDURE - 1.6L

2. ENGINE IGNITION TIMING - Must be set with timing terminal
grounded.
3. ENGINE VACUUM - Must be normal for your altitude.
4. ENGINE VALVE TIMING - To specifications.
5. ENGINE COMPRESSION - To specifications.
6. ENGINE P.C.V. SYSTEM - Must flow freely.
7. ENGINE EXHAUST SYSTEM - Must be free of any restrictions.
8. POWER BRAKE BOOSTER - No internal vacuum leaks.
9. TORQUE CONVERTER CONDITION - May cause very low power at breakaway
or high speed (Only 1 condition at a time).
10. FUEL CONTAMINATION - High alcohol or water content.
11. FUEL INJECTORS - Rough idle may be caused by injector wiring not
connected to correct injector.
12. ENGINE SECONDARY IGNITION CHECK - Abnormal scope patterns.
13. TECHNICAL SERVICE BULLETINS - Any that apply to vehicle.
14. All air intake piping and vacuum hoses must be in place and
secure. The proper air filter element must be used.
15. FUEL PRESSURE - Must be correct.
Specification: With no vacuum at the regulator:
48 PSI on V6 & non-turbo 4 Cyl. engines
36 PSI on turbo engines
NS-1: IGNITION CHECK FLOW CHARTS - 2.0L
Fig. 235: NS-1 Flow Chart & Circuit Diagram (2.0L) (1 of 5)

determined that all of the engine controls systems are operating as
they were designed to. Therefore, they are not the cause of the
driveability problem. The following additional items should be checked
as possible causes:
1) ENGINE VACUUM - Must be at least 13 inches in neutral.
2) ENGINE VALVE TIMING - Set to specifications.
3) ENGINE COMPRESSION - To specifications.
4) EXHAUST SYSTEM - Free from any restrictions.
5) PCV SYSTEM - Must flow freely.
6) DRIVE SPROCKETS - Camshaft and crank shaft.
7) TORQUE CONVERTER STALL SPEED - To specifications.
8) POWER BRAKE BOOSTER - No internal vacuum leak.
9) FUEL CONTAMINATION - High alcohol and water content.
10) FUEL INJECTORS - Rough idle may be caused by injector
control wire not connected to correct injector.
11) TECHNICAL SERVICE BULLETINS - Any that may apply to
vehicle.
12) ENGINE SECONDARY IGNITION CHECK - Any abnormal scope
pattern.
13) TECHNICAL SERVICE BULLETINS - Any that apply to vehicle.
14) All air intake piping and vacuum hoses must be in place
and secure. The proper air filter element must be used.
15) FUEL PRESSURE - Must be correct.
Specification: With no vacuum at the regulator:
48 PSI on V6 & non-turbo 4 Cyl. engines
36 PSI on turbo engines
DR-VER: DRIVEABILITY VERIFICATION TEST - 2.0L
Fig. 300: DR-VER Flow Chart (2.0L)
SUMMARY

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TR AN SM IS SIO N S ER VIC IN G - A /T

1991 M it s u bis h i M onte ro
1991 TRANSMISSION SERVICING
Automatic Transmission
Mitsubishi: Eclipse, Galant, Mirage,
Montero, Pickup, Precis, 3000GT
IDENTIFICATION
MITSUBISHI AUTOMATIC TRANSMISSION APPLICATIONS








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Model Transmission/Transaxle
Eclipse
1.8 & 2.0L ........................... Model F4A22 Transaxle
2.0L Turbo ........................... Model F4A33 Transaxle
All-Wheel Drive (AWD) ................ Model W4A33 Transaxle
Galant
AWD .................................. Model W4A32 Transaxle
DOHC ................................. Model F4A22 Transaxle
SOHC ........................ Model KM175 or F4A22 Transaxle
Mirage
1.5L ................................. Model F3A21 Transaxle
1.6L ................................. Model F4A21 Transaxle
Montero ............................ Model V4AW2 Transmission
Pickup ............................. Model R4AC1 Transmission
Precis ................................ Model KM176 Transaxle
3000GT ................................ Model F4A33 Transaxle









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LUBRICATION
TRANSAXLE/TRANSMISSION SERVICE INTERVALS
Check fluid level every 12 months or 15,000 miles. Change
fluid and filter every 30,000 miles. If vehicle is operated under
severe condition, change fluid more often. If severe darkening of
fluid and strong odor are noted, bands should also be adjusted (if
equipped).
TRANSFER CASE SERVICE INTERVALS
On 4WD and AWD models, change transfer case fluid every 30,
000 miles.
CHECKING FLUID LEVEL
TRANSAXLE/TRANSMISSION
1) Park vehicle on level area. Ensure oil is at normal
operating temperature, parking brake is engaged, and engine is at
idle. Move gear selector through each position, stopping briefly in
each position.
2) Place gear selector in Neutral, and clean area around
dipstick tube. Ensure fluid level is between lower and upper marks,
but never over upper mark, in HOT range. Add or drain fluid if
necessary.

fluid to bring level to lower mark of dipstick if necessary. Recheck
fluid level after transmission is at normal operating temperature.
TRANSFER CASE
Drain plug is located on bottom of transfer case. Change
drain plug gasket whenever fluid is changed. On 3000GT, lubricant
level should be approximately .5" (13 mm) below fill hole on side of
transfer case. On all others models, lubricant level should be to
bottom of fill hole on side of transfer case.
HYDRAULIC CONTROL PRESSURE ADJUSTMENTS
LINE PRESSURE CHECK (EXCEPT MONTERO & PICKUP)
1) Set parking brake. Place shift lever in Neutral position.
Attach engine tachometer. Remove line pressure port plug located above
front transaxle shaft, forward of governor pressure port plug. On
Precis, line pressure port is located below bell housing, at front of
transaxle oil pan. Using appropriate adapter, attach pressure gauge.
2) Start engine, and bring to operating temperature. With
gear selector in Drive position, bring engine speed to 2500 RPM. Pull
throttle control cable (if equipped) wide open at transaxle side.
3) Line pressure should be 98-100 psi (6.9-7.0 kg/cm
) on
Mirage, or 124-127 psi (8.7-8.9 kg/cm) on all others. If line
pressure is not to specification, proceed to LINE PRESSURE ADJUSTMENT.
LINE PRESSURE ADJUSTMENT (EXCEPT MONTERO & PICKUP)
1) Drain transaxle fluid. Remove oil pan. Disconnect throttle
control cable from throttle cam. Remove oil temperature sensor (if
equipped). Disconnect solenoid connector. On some models, it may be
necessary to push solenoid wire harness connector and grommet into
transaxle case.
2) Remove oil filter screen and plate. Noting location and
length of bolts, remove valve body. DO NOT drop internal parts. Adjust
line pressure by turning regulator valve adjusting screw.
3) Turn adjusting screw counterclockwise to increase pressure
or clockwise to decrease pressure. One complete turn of adjusting
screw changes line pressure as follows.
* 3.7 psi (.26 kg/cm
) on Mirage with F3A21 Transaxle
* 5.4 psi (.39 kg/cm) on Precis
* 54 psi (3.8 kg/cm) on all others
4) After adjustment, reverse removal procedure to install.
Refill transaxle.
LINE PRESSURE (MONTERO)
1) Remove plug from line pressure take-off port located
behind transmission shift control lever. Install Hydraulic Pressure
Meter (MD998330) with Adapter (MD998206).
2) Place vehicle on dynamometer. Apply parking brake and
start engine. With brake applied, place transmission in Drive. Note
pressure at idle. Pressure should be 74-85 psi (5.2-6.0 kg/cm
).
3) Raise engine RPM to stall speed (2100-2400 RPM). Note lin\
e
pressure. Pressure should be 156-185 psi (11.0-13.0 kg/cm
).
4) Shift transmission into Reverse with brake applied. At
idle, pressure should be 112-130 psi (7.9-9.1 kg/cm
). Raise engine
RPM to stall speed (2100-2400 RPM). Note line pressure. Pressure
should be 227-285 psi (16.0-20.0 kg/cm
). If readings are not to

specification, use the following trouble shooting guide.
* Hydraulic Pressure High In All Ranges
Check throttle cable adjustment. If adjustment is okay, check
for throttle valve or regulator valve failure.
* Hydraulic Pressure Low In All Ranges
Check throttle cable adjustment. If adjustment is okay, check
for throttle valve, regulator valve, transmission oil pump or
overdrive clutch failure.
* Hydraulic Pressure Low In Drive Position
Check for fluid leaks in Drive hydraulic circuit. Check for
forward clutch or overdrive clutch failure.
* Hydraulic Pressure Low In Reverse Position
Check for fluid leaks in Reverse hydraulic circuit. Check for
transmission No. 3 brake failure, forward clutch failure or
overdrive clutch failure.
LINE PRESSURE (PICKUP)
1) Incorrect throttle pressure setting will cause incorrect
line pressure readings even though line pressure adjustment is
correct. Always inspect and correct throttle pressure adjustment
before adjusting line pressure.
2) Approximate adjustment, measured from valve body to inner
edge of adjusting nut, is 15/16". However, due to manufacturing
tolerances, adjustment can be varied to obtain correct line pressure.
3) Adjusting screw may be turned with an Allen wrench. One
complete turn of adjusting screw changes closed throttle line pressure
approximately 1 2/3 psi. Turn adjusting screw counterclockwise to
increase pressure or clockwise to decrease pressure.
THROTTLE PRESSURE (PICKUP)
1) Throttle pressures cannot be accurately tested. If a
malfunction exists, adjustment should be measured.
2) Insert Gauge Pin (C-3763) between throttle lever cam and
kickdown valve. Push in on tool to compress kickdown valve against its
spring.
3) As force is being exerted to compress spring, turn
throttle lever screw with Allen wrench until head of screw touches
throttle lever tang with gauge pin, and throttle valve bottoms. Ensure
adjustment is made with spring fully compressed and valve bottomed in
valve body.
KICKDOWN BAND
PICKUP
1) Locate kickdown band adjusting screw on left side of
transmission case. Loosen lock nut, and back off nut 5 turns. Ensure
adjusting screw turns freely in transmission case.
2) Using torque wrench, tighten adjusting screw to 72 INCH
lbs. (8 N.m). Back off adjusting screw 2 7/8 turns. Hold adjuster
screw in this position, and tighten lock nut to 30 ft. lbs. (41 N.m).
LOW-REVERSE BAND
PICKUP
1) Raise vehicle, drain transmission, and remove oil pan.
Loosen adjusting screw lock nut, and back off nut 5 turns. Ensure