1991 MITSUBISHI 3000GT check engine

GENERAL - Precautions before Service0045
c
mm (in.)so005
PRECAUTIONS BEFORE SERWCEMOOOAAOSERVICING ELECTRICAL SYSTEM
1. Note the following before proceeding with work on the
electrical system.
Note that the following must never be done:
Unauthorized modifications of any electrical device or
wiring, because such modifications might lead to a vehicle
malfunction, over-capacity or short-circuit that could result
in a fire in the vehicle.
2. When servicing the electrical system, disconnect the
negative cable terminal from the battery.
Caution1. Before connecting or disconnecting the negative
cable, be sure to turn off the ignition switch and the
lighting switch.(If this is not done, there is the possibility of
semiconductor parts being damaged.)
2. After completion of the work steps [when the
battery’s negative (-) terminal is connected], warm
up the engine and allow it to idle for approximately
five minutes under the conditions described below,in order to stabilize the engine control conditions,
and then check to be sure that the idling is
satisfactory.
Engine coolant temperature: 80 - 95°C (176 - 203°F)
Lights, electric fans, accessories: OFF
Transaxle: neutral position(A/T models: “N” or “P”)
Steering wheel: neutral (center) position
VEHICLE WASHING
If high-pressure car-washing equipment or steam car-washing
equipment is used to wash the vehicle, be sure to maintain the
spray nozzle at a distance of at least 300 mm (12 in.) from any
plastic parts and all opening parts (doors, luggage compart-
ment, etc.).
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00-20GENERAL - Special Handling Instructions for AWD Models
14A019fOOPOO38
BalancingmachineOOA0046
Pick-up stand
OOA0024
I
FRONT WHEEL MEASUREMENTS1. Place the front wheels on the brake tester.
2. Perform the brake test.
CautionThe rear wheels should remain on the ground.
3.If the brake dragging force exceeds the specified value, jack
up the vehicle and manually rotate each wheel to check the
rotation condition of each wheel.
NOTEIf the brake dragging force exceeds the specified value, the
cause may be the effect of the viscous coupling’s dragging
force, so jack up the front wheels and check the rotation
condition of the wheels in this state for no effect by the
viscous coupling’s dragging force.
REAR WHEEL MEASUREMENTSAfter placing the rear wheels on the brake tester, follow the
same procedures as for the front wheel measurements.
WHEEL BALANCE
FRONT WHEEL MEASUREMENTS‘d
1. Jack up the rear wheels, and place an axle stand at the
designated part of the side sill.
2. Jack up the front wheels and set a pick-up stand and
balancing machine in place.
Caution
1.Set so that the front and rear of the vehicle are at
the same height.
2. Release the parking brake.
3. Rotate each wheel manually and check to be sure
that there is no dragging.
3. Use the engine to drive the tires, and then make the
measurements.
Caution
1.If an error is indicated in the state of engine drive,
motor drive can be used concurrently.
2. Do not operate the clutch suddenly, or increase or
reduce speed suddenly during the work.
REAR WHEEL MEASUREMENTS1. Jack up the front wheels, and place an axle stand at the
designated part of the side sill.
2. Jack up the rear wheels, and then, after setting a pick-up
stand and balancing machine in place; follow the same
procedure as for front wheel measurements.
\
\L)
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FOR AWD MODELSMOOUAACBRAKE TEST
‘dIn order to stabilize the viscous coupling’s dragging force, the
brake test should always be conducted after the speedometer
test.

GENERAL - Master Troubleshooting
ROUGH IDLE OR ENGINE STALLS
LProbable causeReference page or remedy
Symptom
Rough idle or engine stallsVacuum leaks
l Purge control valve hosel Vacuum hosesl Intake manifoldl Air intake plenuml Throttle bodyl EGR valve
Ignition system problems16-25
Idle speed set too lowCheck idle speed controlsystem
Idle mixture too lean or too rich-
Fuel injection system problems-
Exhaust gas recirculation (EGR) systemproblems17-11
Engine overheats
114-3
Compression too lowIll-15
ENGINE HESITATES OR POOR ACCELERATION
L
Reference pageSymptomProbable cause
Ignition system problem
Vacuum leaksl Purge control valve hosel Vacuum hosesl Intake manifoldl Air intake plenuml Throttle bodyl EGR valve
Air cleaner clogged
Fuel line clogged
Fuel injection system problem
Emission control system problem
l EGR system always on
Engine overheats
Compression too low11-13
Engine hesitates or poor
acceleration
17-3
15-9
-
17-11
14-3
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00-36GENERAL - Scheduled Maintenance Table / Maintenance Service
SCHEDULED MAINTENANCE UNDER SEVERE USAGE CONDITIONS
The maintenance items should be performed according to the following table:
Mileage Intervals Kilometers in ThousandsSevere Usage
MaintenanceService to be(Miles in Thousands)Conditions
itemPerformed
(6 (15) (22.5) (30) (37.5) (45) (50) (52.5) (60)24 36 48 60 72 80 84 96 A B C D E F G
Air Cleaner ElementReplaceMore FrequentlyXX
Spark PlugsReplaceXXXXXX
Engine OilChange Every Or3 MonthsEvery 4,800 Km (3,000 Miles)x x x xX
Engine Oil FilterReplace Every or6 MonthsEvery 9,600 Km (6.000 Miles)x x x xX
Disc Brake PadsInspect for WearMore FrequentlyXX
Severe usage conditions
A-Driving in dusty conditionsE -B -Police, taxi, or commercial type operationF -Driving in sandy areas
C -Extensive idlingG -Driving in salty areas
D -Short trip operation at freezing temperaturesMore than 50% operation in heavy city traffic during
(engine not thoroughly warmed up)hot weather above 32°C (90°F)MAINTENANCE SERVICE
1. FUEL SYSTEM (TANK, LINES, CONNECTIONS
AND FUEL FILLER CAP) (Check for leaks)
/ 2.
FUEL HOSES (Check for leaks or damage)MWShGC
1. Check for damage or leakage in the fuel lines and
connections and looseness of the fuel filler cap.
2.Inspect the surface of fuel hoses for heat and mechanical
damage. Hard and brittle rubber, cracking, checking, tears,
cuts, abrasions and excessive swelling indicate deteriora-
tion of the rubber.
3.If the fabric casing of the rubber hose is exposed by cracks
and abrasions in the fuel system, the hoses should be
changed.
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00-38GENERAL - Maintenance Service
6. DRIVE BELT (For Alternator)
00F0006
:Vehicles with air conditioner>OOFOO07
A: Crankshaft pulleyB: Tension pulleyC: Alternator pulleyD: Idler pulleyE: ,Air conditioner compressor pulley
OlLO183
OlLO18:(Inspect tension)
MOOS88(1(1) Measure the deflection with a force of
100 N (22 Ibs.)applied to belt mid-point between pulleys shown in the
illustration. If the standard value is not obtained, make
adjustment.
Standard value: 4.0
- 5.5 mm (.157 - 216 in.)
(2) On vehicles without air conditioner, set a tension gauge at a
position marked with
r3 in the illustration to measure the
belt tension.
7. ENGINE OIL
(Inspect oil level)
(I) Check to see that the engine oil level is within the range
indicated on the oil level gauge.
(2) Make sure that engine oil is not very dirty or is free from
coolant or gasoline and has an appropriate viscosity grade.J
(Change)
MOOSAAHAlways use lubricants which conform to the requirements of
the API classification “For Service SG” or “For Service
SGKD”when available, and have the proper SAE grade number for the
expected temperature range.
Never use nondetergent or straight mineral oil.
(1) After warming up the engine, remove the oil ‘filler cap.
(2) Remove the drain plug and drain the engine oil.
(3) Tighten the drain plug to 40 Nm (29 ft.lbs.).
(4) Pour new engine oil through the oil filler.
Caution
1.Cover the alternator with waste cloth or the like before
pouring engine oil to make sure that even if oil is spilt,it may not drop on the alternator.
2. Use an oil mug or a funnel to pour oil.
Engine oil total capacity:4.0 liters (4.2 qts.)
[excluding oil filter 0.3 liter (l/2 qt.)
and oil cooler 0.21 liter (l/2 qt.)](5) Check to ensure that the engine oil level is within the level
range indicated on the oil dip stick.
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GENERAL - Maintenance Service00-39ogPOO268. ENGINE OIL FILTER (Change)
MOOEAEJThe quality of replacement filters varies considerably. Only high
quality filters should be used to assure most efficient service.
Genuine oil filters require that the filter be capable of
withstanding a pressure of 256 psi are high quality filters and
are recommended as follows:
Oil Filter Part No.
MITSUBISHI Genuine Parts: MD136790
ENGINE OIL FILTER SELECTIONThis vehicle is equipped with a full-flow, throw-away oil filter.
The same type of replacement filter is recommended as a
replacement filter for this vehicle. It is possible, particularly in
cold weather, that this vehicle may develop high oil pressure
for a short duration. You should be sure that any replacement
filter used on this vehicle is a high-quality filter and is capable of
withstanding a pressure of 256 psi (1,765
kpa) (manufacturer’s
specifications) to avoid filter and engine damage. The following
is a highquality filter and is strongly recommended for use on
this vehicle: Mitsubishi Engine Oil Filter P/N MD136790.
Any replacement oil filter should be installed in accordance with
the oil filter manufacturer’s installation instructions.
(1) Remove the engine oil filter by using the oil filter wrench.
(2) Clean the oil filter mounting surface of the oil filter bracket.
(3) Coat engine oil to the O-ring of new oil filter.
(4) Turn the oil filter by hand and install to the filter bracket.
NOTEThe oil filter tightening torque is 14 Nm (11
ft.lbs.1.(5) Start and run engine and check for engine oil leaks.
(6) After stopping engine, check oil level and refill as neces-
sary.
9. MANUAL TRANSAXLE (Inspect oil level)
MOOSBCGInspect each component for evidence of leakage, and check
the oil level by remaining the filler plug. If the oil is contami-
nated, it is necessary to replace it with new oil.
(1) With the vehicle parked at a level place, remove the filler
plug.
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GENERAL - Maintenance Service00-41
Good
t-lVA0283
I04FOOOd(4) Check the oil filter for clogging and damage and replace if
necessary.
(5) Clean drain plug and tighten drain plug with gasket to 30
-35 Nm (22
- 25 ft.lbs.).
(6) Clean both gasket surfaces of transaxle case and oil pan.
(7) Install oil pan with new gasket and tighten oil pan bolts to
10 - 12 Nm (7.5 - 8.5 ft.lbs.).
(8) Pour 4.5 liters (4.8 qts.) of specified ATF into case through
dipstick hole. [Total quantity of ATF required is approx. 7.5
liters (7.9 qts.). Actually however, approx. 4.5 liters (4.8 qts.)
of fluid can be replaced because rest of fluid remains in
torque converter.]
Specified fluid: Dia ATF SP or MITSUBISHI PLUS ATF or
equivalent(9) Start engine and allow to idle for at least two minutes.
Then, with parking brake on, move selector lever momen-
tarily to each position, ending in “N” Neutral position.
(lO)Add sufficient ATF to bring fluid level to lower mark.
Recheck fluid level after transaxle is at normal operating
temperature. Fluid level should be between upper and
lower marks of “HOT” range. Insert dipstick fully to prevent
dirt from entering transaxle.
11. ENGINE COOLANT (Change)
MOOSBEHCheck the cooling system parts, such as radiator, heater, and
oil cooler hoses, thermostat and connections for leakage and
damage.
CHANGING COOLANT
1.
2.
3.
4.
5.
6.
7.
8.Remove te heat protectors (front and rear) from the exhaust
manifold.
Loosen the radiator drain plug, remove two drain plugs from
the engine block (one for each bank) and remove the
radiator cap to discharge coolant.
Remove the reservoir tank and discharge coolant.
When coolant has been discharged, pour water through the
filler port to flush coolant passage.
Coat the threads of the engine drain plugs with the
specified sealant and tighten the plugs to specification.
Specified sealant: 3M Nut Locking Part No. 4171 or
equivalentTightening torque: 40 Nm (29
ftlbs.)Fit the radiator drain plug securely.
Mount the reserve tank.
Slowly pour coolant into the radiator to the brim and also
into the reserve tank up to the FULL line.
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00-42GENERAL - Maintenance Service
14UOO729. Install the radiator cap securely.
10.
Start’the engine and warm up until the thermostat opens.
11. Race the engine up to around 3,000 rpm several times, then
stop the engine.,12. When the enkine has cooled down, remove the radiator cap
L/and add coolant up to the brim. Add coolant to the reserve
tank up to the FULL line.

1. Lift up the vehicle.
2.Loosen the radiator drain plug, remove the drain plug from
the rear bank of the engine and remove the radiator cap to
discharge coolant.
3. Follow the same steps 3 to 12 above.
12.DISC BRAKE PADS (Inspect for wear)MOOSBFDCheck for fluid contamination and wear. Replace complete set
of pads if defective.
Caution
The pads for the right and left wheels should be replaced atIIthe same time. Never “split” or intermix brake pad sets. AllUfour pads must be replaced as a complete set.
Thickness of lining (A):
Limit2.0 mm (.08 in.)
13. BRAKE HOSES (Check for deterioration or
leaks)
MOOSBHBInspection of brake hoses and tubing should be included in all
brake service operations.
The hoses should be checked for:
1.Correct length, severe surface cracking, pulling, scuffing or
worn spots. (If the fabric casing of the hoses is exposed by
cracks or abrasion in the rubber hose cover, the hoses
should be replaced. Eventual deterioration of the hose may
occur with possible bursting failure.)
2. Faulty installation, casing twisting or interference with
wheel, tire or chassis.
14. BALL JOINT AND STEERING LINKAGE SEALS
(Inspect for grease leaks and damage)
MOOSglC1. These components, which are permanently lubricated at
the factory, do not require periodic lubrication. Damaged
seals and boots should be replaced to prevent leakage or
contamination of the grease.
2.Inspect the dust cover and boots for proper sealing, leakageIdand damage. Replace them if defective.
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