1991 MITSUBISHI 3000GT service

FUEL
SYSTEM
CONTENTSM13AA- _
CRUISE CONTROL SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . .158SPECIFICATIONS. . . . . . . .._._....................................................155
CRUISE CONTROL SYSTEM*................................................185
SERVICE ADJUSTMENT PROCEDURES............................178
Cruise Control Cables Inspection and Adjustment........178Cruise Control SystemInspection....................................179individual Parts Inspection....................................................181
SPECIAL TOOLS........................................................................159
SPECIFICATIONS....................................................................158
General Specifications........................................................158Service Specifications........................................................158
TROUBLESHOOTING............................................................159
Check Chart............................................................................163Harness and Components Layout....................................176Preliminary Inspection........................................................159Self-diagnosis Checking........................................................172Troubleshooting Quick Reference Chart............................159
ENGINE CONTROL............................................155
ENGINE CONTROL................................................................157
SERVICE ADJUSTMENT PROCEDURES............................156
Accelerator Cable Inspection and Adjustment................156Accelerator Switch Inspection and Adjustment................156
Service Specifications........................................................
155
TROUBLESHOOTING............................................................
155
Accelerator Cable and Accelerator Pedal........................155
FUEL SYSTEM....................................................3
DETONATION SENSOR........................................................154
FUEL FILTER............................................................................
153
FUEL LINE AND VAPOR LINE................................................151
FUEL PUMP AND FUEL GAUGE UNIT ASSEMBLYAND OVERFILL LIMITER (TWO-WAY VALVE)................149
FUEL TANK.................................................................................146
GENERAL INFORMATION
....................................................
3
MPI System Diagram............................................................3
INJECTOR................................................................................141
ON-VEHICLE INSPECTION OF MPI COMPONENTS........36
Active Exhaust Control Unit ............................130Air Conditioner Switch and Power Relay............................82Air Flow Sensor....................................................................54Anti-lock Brake Signal ........................................133Barometric Pressure Sensor................................................60CONTINUED ON NEXT PAGE
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
(1)A Supplemental Restraint System (SRS), which uses a driver-side air bag, has been installed in the 3000GT.(2)The SRS includes the following components: impact sensors, SRS diagnosis unit: SRS warning light, air bagmodule, clock spring, interconnecting wiring. Other SRS-related components (that may have to be
removed/installed in connection with SRS service or maintenance) are indicated in the table of contents byan asterisk (*).
WARNING!(I)Improper service or maintenance of any component of the SRS, or any SRS-related component, can lead to
personal injury or death to service personnel (from inadvertent firing of the air bag) or to the driver (from
rendering the SRS inoperative).
(2) Service or maintenance of any SRS component or SRS-related component must be performed only at anauthorized MITSUBISHI dealer.
(3) MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP
528 -Supplemental Restraint System (SRS), before beginning any service or maintenance of any component of theSRS or any SRS-related component.

13-2
Boost Meter ........................................................128Components Inspection Procedure....................................40
Components Location........................................................36
Crank Angle Sensor
............................................................72Detonation Sensor................................................................84EGR Control Solenoid Valve
........................................121
EGR Temperature Sensor ............................92ElectricalLoad Switch........................................................86Engine and Transaxle Total Control Signal ............135Engine Control Unit Power Ground....................................44Engine Coolant Temperature Sensor................................62Fuel Pressure Control Valve ............................123Fuel Pressure Test................................................................138Fuel Pump ....................................................45Fuel Pump ............................................................48
Fuel Pump Operation Check................................................137Fuel Pump Relay No. 2........................................................53Fuel Pump Resistor............................................................53
Idle Position Switch............................................................68Idle Speed Control Servo (Stepper Motor Type)............1 IOIgnition Coil and Power Transistor....................................115Ignition Switch-ST and Inhibitor Switch ................76Ignition Switch-ST ................................................75Induction Control Valve Position Sensor
........................................................................90
Injectors........................................................101Injectors................................................................105Intake Air Temperature Sensor............................................57Muffler Mode Changeover Switch ....................88Oxygen Sensor ............................................
94
Oxygen Sensor ....................................................98
Power Steering Oil Pressure Switch................................80Power Supply and Ignition Switch-IG................................41
Purge Control Solenord Valve............................................1 19Release of Residual Pressure from High
Pressure Fuel Hose............................................................137Throttle Position Sensor....................................................65Top Dead Center Sensor....................................................70Variable Induction Control Servo (DC Motor)
........................................................................131Vehicle Speed Sensor........................................................78Waste Gate Control Solenoid Valve ................126
SERVICE ADJUSTMENT PROCEDURES............................31
Adjustment of Fixed SAS....................................................35Adjustment of Idle Position Switch and
Throttle Position Sensor (TPS)............................................33Basic Idle Speed Adjustment............................................31Throttle Body (Throttle Valve Area) Cleaning....................33
SPECIAL TOOLS........................................................................8
SPECIFICATIONS
....................................................................6
General Specifications........................................................6Sealant....................................................................................7Service Specifications........................................................7
THROlTLE BODY....................................................................143
TROUBLESHOOTING............................................................9
Check Chart Classified by Problem Symptoms................16Circuit Diagram....................................................................18Engine Warning Light (Malfunction Indicator Light)........11Explanation and Cautions about Harness Check............10Explanation of Troubleshooting Procedures....................9Fuel Tank and Fuel Line........................................................30
Problem Symptoms Table (For Your Information)............17Self-diagnosis........................................................................12)
I

FUEL SYSTEM - SDecifications
L
Items
Actuators
Control relay type
Injector type and number
Injector identification mark
Variable induction control servo
Purge control solenoid valve
EGR control solenoid valve

Fuel pressure control solenoid valve
Waste gate solenoid valve
Fuel pressure regulator
Regulated pressure
kPa (psi)
Specifications
Contact switch type
Electromagnetic, 6
BDH210
BDL360
Electric motor
ON/OFF type solenoid valve
Duty cycle solenoid valve
ON/OFF type solenoid valve
Duty cycle type solenoid valve
335 (47.6)
300 (43.5)
SERVICE SPECIFICATIONS
i
ternsSpecifications
3asic ignition timing5” -t 2”BTDC at curb idle
3urb idle speedrpm700 * 100
dle speed when air conditioner is on
rpm
900 at neutral position
650 at D range
3asic idle speedrpm700 + 50
Throttle position sensor adjusting voltageV0.4- 1 .o
Throttle position sensor resistancek03.5 - 6.5
dle speed control servo (stepper motor) coil resistance028 - 33 [at 20°C (68”F)I
ntake air temperature sensor resistancekfi2.7 [at 20°C (68”F)I
Engine coolant temperature sensor resistancekQ
20°C (68°F)
2.4
80°C (176°F)0.3
%el pressurekPa (psi)
Vacuum hose disconnection 330 - 350 (47 - 50) at curb idle
295 - 315 (43 - 45) at curb idle
Vacuum hose connection Approx. 270 (38) at curb idle
Approx. 235 (34) at curb idleInjector coil resistance
Sz 13 - 16 [at 20°C (68”F)]
2 - 3 [at 20°C (68”F)I
SEALANTMlXE-A
IItems1 Specified sealantI
/
L
Engine coolant temperature sensor threaded portion3M NUT Locking Part No. 4171 or equivalent
Fuel tank hole cover3M ATD Part No. 8509 or equivalent
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SERVICE ADJUSTMENT PROCEDURES
MlBFHSU
BASIC IDLE SPEED ADJUSTMENT
NOTE(1) The basic idle speed has been factory-adjusted with the
speed adjusting screw (SAS) and does not normally require
adjustment.(2) If the adjustment is required, first check that the ignition
plug, injector,
ISC servo, and compression pressure are
normal.
(1) Before starting the inspection and adjustment procedures,set the vehicle in the following conditions:
l
Engine coolant temperature: 80 to 95°C (176 to 205°F)l Lights, electric cooling fan, accessories: OFF
lTransaxle: Neutral (P range on vehicles with automatic
transaxle)l Steering wheel: Straightforward position
(2) When using the multi-use tester, connect it to the diagnosis
connector.
NOTEThe connection of the multi-use tester grounds the
self-
diagnosis/data transmission selector terminal.
(3) When not using the multi-use tester, proceed as follows:
@) Insert a paper clip into the l-pin blue connector as
shown in the illustration. FUEL SYSTEM
- Service Adjustment Procedurks13-31
i
@ Connect a primary-voltage-detecting tachometer to the
paper clip.
NOTEThe
tacho/neter should read l/3 of the actual engine
speed. This means that the actual engine speed is thetachometer reading multiplied by 3.
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13-32FUEL SYSTEM - Service Adjustment Procedures
@ Using a jumper wire, ground the self-diagnosis/data
transmission selector terminal (terminal
@) of theI
diagnosis connector (white).
dSelf-diagnosis/
ydata transmission
(4) Remove the waterproof female connector from the ignition
timing adjusting connector (brawn).(5) Using a jumper wire, ground the ignition timing adjusting
terminal.(6) Start the engine and run at idle.
(7) Check the basic idle speed.
When using the multi-use tester, select item No. 38 and
read the idle speed.
Basic idle
speeci: 700 + 50 rpm
NOTE(I) The engine speed may be low by 20 to 100 rpm while
the vehicle is new [distance driven approx. 500 km (300miles) or less], but no adjustment is necessary.
(2) If the engine stalls or speed is low despite a sufficient
distance driven [approx. 500 km (300 miles) or more], it
is probably due to deposits on the throttle valve. In thiscase, clean the throttle valve. (Refer to
P.13-33.)(8) If the basic idle speed is out of specification, adjust by
turning the speed adjusting screw (SAS).
NOTE
If the idle speed is higher than the standard value even with
SAS fully tightened, check to see if there is evidence of theidle switch (fixed SAS) being moved. If the idle switch
seems to have been moved, adjust it. If it does not seem tohave been moved, there may be a leak caused by
deteriorated fast idle air valve (FIAV). In such a case, replacethe throttle body.
(9) Turn the ignition switch OFF.
(lO)When the multi-use tester has not been used, remove thejumper wire from the self-diagnosis/data transmission
selector terminal.
(11)Remove the jumper wire from. the ignition timing adjustingterminal and replace the connector back again.
(12)Start the engine again and run at idle for
10 minutes to
make sure that the engine runs at proper idle speed.
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FUEL SYSTEM - Service Adjustment Procedures13-33THROTTLE BODY
(THROTrLE VALVE AREA)
CLEANINGM13FICS
(1) Start the engine, warm it up until engine coolant tempera-ture rises to
80°C (176”F), and stop the engine.
(2) Disconnect the air intake hose at the throttle body side.
(3) Put a plug in the inlet of bypass passage in the throttle
body.
CautionNever allow cleaning agent to flow into the bypass
passage.(4) Spray cleaning agent from the intake port of the throttle
body to the valve and leave as it is for 5 minutes or so.
(5) Start the engine and race it several times. Then, run it idlefor approx. one minute.
NOTE
If the engine idle speed becomes unstable (and fails in theworst case) after plugging the bypass passage, run the
engine with the throttle valve slightly opened.
(6) If the deposit cannot be removed from the throttle valve,
repeat steps (4) and (5).
(7) Disconnect the plug from the inlet of the bypass passage.(8) Install the air ‘intake hose.
(9) Use a multi-use tester to erase the self-diagnosis code ordisconnect the battery ground cable for more than
IOseconds and then connect it again.
(lO)Adjust the basic idle speed (speed adjusting screw). (Referto
P.13-31.)
7FUO629
ADJUSTMENT OF IDLE POSITION SWITCH AND
THROTTLE POSITION SENSOR (TPS)M13FIFA(1) Disconnect the throttle position sensor connector.
(2) Using jumper wires, connect an ohmmeter across terminal
@ (idle position switch) and terminal @ (sensor ground) ofthe throttle position sensor.
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FUEL SYSTEM - Service Adjustment Procedures
(3) Insert a 0.65-mm-thick feeler gauge between the fixed SASand throttle lever.
Terminal @
(sensor output)zensor g&nd)MB991348
1
(4) Loosen the throttle position sensor mounting bolts and turnthe TPS body fully counterclockwise.
(5) In this condition, check that there is continuity across
terminals
@ and @.
(6) Slowly turn the throttle position sensor clockwise until you
find a point at which there is no continuity across terminals
@ and 0. Then, tighten the throttle position sensor
mounting bolt securely.(7) Connect the throttle position sensor connector.
(8) When using the multi-use tester, connect it to the diagnosis
connector.
(9) When not using the multi-use tester, proceed as follows:
@ Disconnect the throttle position sensor connectors andconnect the special tool, Test Harness Set, between
the disconnected connectors.
@ Connect a digital voltmeter between the throttle posi-
tion sensor terminal @ (sensor output) and teminal @
(sensor ground).
(lO)Turn the ignition switch ON (but do not start the engine).
(IlKheck the throttle position sensor output voltage.
When using the multi-use tester, select item No. 14 and
read the throttle position sensor output voltage.
Standard value: 400 - 1,000 mV
(12)lf the voltage is out of specification, check the throttle
position sensor and associated harnesses.
(13)Remove the feeler gauge.
(14)Turn the ignition switch OFF.
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1

FUEL SYSTEM - Service Adjustment Procedures13-35
ADJUSTMENT OF FIXED SASMlJFlDC
NOTE
(1) The fixed SAS has been factory-adjusted. Never attempt tomove it.
(2) Should it be out of proper adjustment, adjust by following
the procedure given below.(I) Sufficiently slacken the accelerator cable.
(2) Loosen the lock nut on the fixed SAS.
(3) Sufficiently loosen the fixed SAS by turning it counterclock-wise to fully close the throttle valve.
(4) Tighten the fixed SAS slowly to find a point at which it
contacts the throttle lever (where the throttle valve starts
opening). From that point, tighten the fixed SAS further 1 l/4
turns.
(5) Holding the fixed SAS to prevent it from turning, tighten thelock nut securely.
(6) Adjust the accelerator cable tension. (Refer to
P.13-156.)(7) Adjust the basic idle speed. (Refer to
P.13-31.)
(8) Adjust the idle position switch and throttle position sensor
(TPS). (Refer to P.13-33.)
1 TSB Revision