ignition MITSUBISHI 3000GT 1991 User Guide

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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FUEL SYSTEM - Troubleshooting13-11
L
L
Sensor side6FU1215
Malfunctionl
If the sensor impressed voltage is abnormal, check the wire
for an open circuit or short-circuit to ground and repair as
necessary. If the wire is normal, replace the engine control
unit and check again.l To check the voltage, use a digital voltmeter (or circuit
tester) as a rule.
[However, use an analog voltmeter for checking the power
transistor drive voltage.]ENGINE WARNING LIGHT (MALFUNCTION IN-
DICATOR LIGHT)
Among the self-diagnosis items, a malfunction indicator lightcomes on to notify the driver of the emission control items
when an irregurality is detected.
However, when an irregular signal returns to normal and theengine control unit judges that it has returned to normal, the
malfunction indicator light goes out.
Moreover, when the ignition switch is turned off, the light goes
out. Even if the ignition switch is turned on again, the light doesnot come on until the irregularity is detected.
Here, immediately after the ignition switch is turned on, the
malfunction indicator light is lit for 5 seconds to indicate that
the malfunction indicator light operates normally.
ITEMS INDICATED BY THE MALFUNCTION INDICATOR
LIGHT
Engine control unit
Oxygen sensor
Air flow sensor
Intake air temperature sensor
Throttle position sensor
Engine coolant temperature sensor
Crank angle sensor
Top dead center sensor
Barometric pressure sensor
Detonation sensor
Ignition timing adjustment signal
Injector
EGR system
Ignition coil, power transistor unit
Caution
The malfunction indicator light comes on when the line ofthe ignition timing adjustment terminal is shorted to
ground. Therefore, the light also comes on when the
ignition timing adjustment terminal is grounded to adjust
the ignition timing, but this does not show any abnormal-
ity.
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13-12FUEL SYSTEM - Troubleshooting
MALFUNCTION INDICATOR LIGHT INSPECTION
(1) Check that when the ignition switch is turned on, the lightilluminates for about 5 seconds and then goes out.
(2) If the light does not illuminate, check for open circuit in
dharness, blown fuse and blown bulb.
SELF-DIAGNOSIS
The engine control unit monitors the input/output signals (some
signals at all times and the others under specified conditions) ofthe engine control unit.
When it is noticed that an irregularity has continued for a
specified time or longer from when the irregular signal is
initially monitored, passing a certain number, the engine controlunit judges that an irregularity has occurred, memorizes the
malfunction code, and outputs the signal to the self-diagnosis
output terminal.
There are 21 diagnosis items, including the normal state, andthe diagnosis results can be read out with a voltmeter or
multi-use tester.Moreover, since memorization of the malfunction codes is
backed up directly by the battery, the diagnosis results are
memorized even if the ignition key is turned off. The malfunc-
tion codes will, however, be erased when the battery terminalor the engine control unit connector is disconnected.
The malfunction code can also be erased by turning on the
ignition switch and sending the malfunction code erase signalfrom the multi-use tester to the engine control unit.
CautionIf the sensor connector is disconnected with the ignition
_ _switch turned on, the malfunction code is memorized. Ind
this case, send the malfunction code erase signal from themulti-use tester to the engine control unit or disconnect
the battery terminal
(-) for 10 seconds or more, and the
diagnosis memory will be erased.
The 21 diagnosis items are provided as follows, and if plural
items are activated, they are all indicated sequentially from the
smallest code number.
CautionThe malfunction code for the ignition timing adjustment
signal is output when the line of the ignition timing
adjustment terminal is shorted to ground. Therefore, the
malfunction code is also output when the ignition timing
adjustment terminal is grounded to adjust the ignition
timing, but this does not show any abnormality.
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13-14FUEL SYSTEM - Troubleshooting
routput
preference
order
7Diannosis item
Diagnosis code
IOutput signal patternNo.
36
39
121 Ignition timing
adjustment signalH
L
13Oxygen sensor ’(Turbo: Front bank)HRetainedl Harness and connectorl Oxygen sensorl Fuel pressurel Injectors (Replaceif defective)l Intake air leaks
Retained
l Harness and connectorl Injector coil resistance
5
I--
Injector12AOlO!
:nnnn
EGR
12A0105
14
41
Retainedl Harness and connectorl EGR thermo-sensorl EGRvalvel EGR control solenoidvalvel EGR valve controlvacuum
Retainedl Harness and connectorl Ignition coill Power transistor unit
16
lqnition coil,
12A0105
52power transistor unitINO. 2-5 cylinder)H
Lu Lnll
‘qnition coil.
12AO105
18Retainedl Harness and connectorl Ignition coill Power transistor unit
Retainedl Harness and connector(If harness and connector
are normal, replace only
transaxle control unit.)
Retainedl Harness and connector(If harness, connector
and induction control
valve are normal,
replace air intake
plenum assembly.)
--
Tower transistor unitH‘NO. 3-6 cylinder)
Ln
12A0105
A cable from trans-
axle control unit,Hfor transmission
of torque reductionLUUUUUI n
signal 12A0105
Induction control
valve position
61
62
sensorHLuutJvL
12A0105
Normal stateH-
NOTE-Replace the engine control unit if a malfunction code is output although the inspection reveals that there is no problem with the check
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FUEL SYSTEM - Troubleshooting13-15READ OUT OF MALFUNCTION CODE
Precautions for Operation
(1) When battery voltage is low, no detection of failure is
possible. Be sure to check the battery for voltage and otherconditions before starting the test.
(2) Diagnosis item is erased if the battery or the engine controlunit connector is disconnected. Do not disconnect the
battery before the diagnosis result is completely read.
Using Multi-Use Tester
(I) Read and record the self-diagnosis output.
(2) Referring to the diagnosis chart, repair the faulty part.
(3) Turn the ignition switch OFF and then turn it ON.
(4) Erase the malfunction code.(5) Recheck that a normal code is output.
7FUO999
r MPI diagnosis
L Ground
EC165(Using Voltmeter(I) Connect an analog voltmeter between the self-diagnosis
output terminal of the diagnosis connector and ground
terminal.(2) Turn on the ignition switch.
(3) Read the diagnosis output pattern from the voltmeter and
record it.(4) Referring to the diagnosis chart, repair the faulty part.
(5) Erase the malfunction code using the following procedure.
@ Turn OFF the ignition switch.
@ Disconnect the negative battery cable from the battery
terminal for
10 seconds or more and then reconnect it.
@ Turn ON the ignition switch and read the self-diagnosiscode to check that a normal code is output.
Diagnosis by DIAGNOSIS 2 MODE
(1) Using the multi-use tester, changeover the diagnosis modeof the engine control unit to DIAGNOSIS 2 MODE.
(2) Road test the vehicle.
(3) Read the diagnosis code in the same manner as “READ
OUT OF MALFUNCTION CODE” and repair the malfunc-
tioning part.(4) Remove the multi-use tester.
NOTERemoval of the multi-use tester
.will erase all the self-’
diagnosis malfunction codes in the engine control unit and
changeover the diagnosis mode from DIAGNOSIS 2 MODEto DIAGNOSIS 1 MODE.
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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 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

13-36FUEL SYSTEM - 0
n-vehicle Inspection of MPI Components
ON-VEHICLE INSPECTION OF MPI COMPONENTS
COMPONENTS LOCATION
EGR control solenoid valve
temperature sensor
Engine control unit
Engine coolant temperature sensor
Engine warning light
Fuel pressure control valve
Ignition coil (power transistor)
Ignition timing adjusting terminal
SSelf-diagnosis output terminal and self-diagnosis/Rdata transmission selector terminal
BTDC sensor and crank angle sensorD
PThrottle position sensor (with built-in idle switch)C
vVariable induction control servo (DC motor)J(with built-in induction control valve position
sensor)
MVehicle speed sensor (reed switch)F
QWaste gate solenoid valve U
NOTEThe “Name” column is in alphabetical order.TSB Revision