light MITSUBISHI 3000GT 1991 Owner's Manual

13-86FUEL SYSTEM - On-vehicle Inspection of MPI Components
ELECTRICAL LOAD SWITCH16FO29;
Tail-lightrelayDefog.wrelaystoplight
t;1
switch
ti* . .
Engine control unit connector
Engine
control
unit7FUO653
7FUO688OPERATION
lThe electrical load switch inputs ON/OFF state of the switch of equipment that consumes much powerduring idling, namely, equipment with a large electrical load, to the engine control unit. Based on this
signal, the engine control unit controls the idle-speed control servo.
l
When the switch of equipment with a large electrical load is turned ON, the battery voltage is applied tothe engine control unit to indicate that the equipment switch is turned ON.,
LJINSPECTION
Using Multi-use Tester
Function
Data reading
I
tem No. Data display
-I-
33Switchstate
Check condition
Equipment stateNormal display
$;ration of equipment:L$ing;Atch only:OFF + ON-3
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FUEL SYSTEM - On-vehicle InsDection of MPI ComDonents
/
idHARNESS INSPECTION
Engine control
unit harness
side connector7FUO689
side connector7FuO689
PU
Engine control
unit harness
side connectorT7FUO689
Measure the input voltage of engineIcontrol unit.
lEngine control unit connector:
Disconnectedl Lighting switch: ON
(Tail light relay ON)
Measure the input voltage of enginecontrol unit.
lEngine control unit connector:
Disconnectedl Defogger switch: ON
(Defogger relay ON)Voltage
(V)
Isv
cl3
Check circuit
related to de-
fogger relay
Measure the input voltage of enginecontrol unit.
lEngine control unit connector:
Disconnected
l Brake pedal: Depressed(Stop light switch ON)
Check circuitTSB Revision

FUEL SYSTEM - On-vehicle Inspection of MPI Components
EGR TEMPERATURE SENSOR M13YZh82
EGR tem0erature senso
7FUlOlO
@ Equipment s,de EGR temperature sensor
connectorII@ Harness side
Enginecontrol
unit
I Iconnector
7FU1013I
Temperature1621008
OPERATIONl
The EGR temperature sensor converts the temperature of EGR gas downstream from the EGR valve to
voltage and inputs it to the engine control unit. The engine control unit judges the condition of the EGR bythis signal. If there is abnormal condition, the engine warning light is turned on to notify the driver.
l
Five volt power supply in the engine control unit is applied to the EGR temperature sensor through the
resistance in the unit. This power supply further passes through the EGR temperature sensor, which is a
kind of a resistor, and is grounded at the engine control unit. The resistance of the EGR temperature
sensor is characterized by a decrease in resistance with an increase of EGR temperature due to increasein quantity of EGR.
l EGR temperature sensor terminal voltage increases or decreases with EGR temperature sensor
resistance. Therefore, EGR temperature sensor terminal voltage changes with EGR gas temperature. Thehigher the EGR gas temperature, the lower the EGR temperature sensor terminal voltage.
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13-114FUEL SYSTEM - On-vehicle Inspection of MPI Components
(5) With the idle speed control servo as shown in the
illustration, connect the negative
0 terminal of the power
supply to each clip as described in the following steps, and
check whether or not a vibrating feeling (a feeling of very
(slight vibration of the stepper motor) is generated as aJresult of the activation of the stepper motor.@Connect the negative
0 terminal of the power supply to
the red and black clip.@Connect the negative
0 terminal of the power supply to
the blue and black clip.@Connect the negative
0 terminal of the power supply to@the blue and yellow clip.
Connect the negative
0 terminal of the power supply to
the red and yellow clip.@Connect the negative
0 terminal of the power supply to
the red and black clip.@ Repeat the tests in sequence from @ to
0.(6) If, as a result of these tests, vibration is detected, the
stepper motor can be considered to be normal.
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13-116FUEL SYSTEM - 0
n-vehicle Inspection of MPI Components
INSPECTION
Using Multi-use Tester
(d
FunctionItem No. Data displayCheck condition
Engine state
Standard valueData reading 44
Ignitionadvancel Engine: Warming up
750 rpm (Idle)7 - 23”BTDCl Timing light: Set (settiming light to check2,000 rpm30 - 40”BTDC actual ignition timing)28 - 35”BTDC

‘
Function
Data listItem No.Data displayCheckTerminalStandard value
condition
condition
36Continuity present or
not present betweenl Engine:
IdlingIgnition timing ad-ON
ignition timing adjustmentjustment terminal isterminal and groundgrounded
Ignition timing ad-OFFjustment terminal is
disconnected from
ground
Function
Actuator testItem No.
DriveCheck conditionNormal condition
17Set to ignition timingl Engine: idling5”BTDCadjustment model Timing light: set\
($Gizi)
IJ
\LIOV _
ovep~,. ..~_~.~ fA t---.-
I
Normal waveform03AO207
(
j /’ II
IOV _I ’/
/ 1ovIJ
Normal waveform
Using Oscilloscope1. Primary signal of ignition coil
(I) Run the engine at an idle revolution speed.
(2) Connect the probe to oscilloscope pick-up point 1 as
shown in the circuit diagram, and check the primary
signal of the ignition coil.
2. Control signal of power transistor
Connect the probe to oscilloscope pick-up point
2 as shown
in the circuit diagram, and check the control signal of the
power transistor.
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13-140FUEL SYSTEM - On-vehicle Inspection of MPI Components
(14)Stop the engine and check for a change of the value
indicated by the fuel pressure gauge. The condition is
normal if there is no decrease of the indicated value within~
two minutes.
,If there is a decrease of the indicated value, monitor the
:d ’speed of the decrease, and, referring to the table below,
determine the cause of the problem and make the
appropriate repair.
Condition
After the engine is stopped, thefuel pressure drops gradually.Probable cause
Injector leakage.
Leakage at the fuel pressure
regulator valve seat.Remedy
Replace the injector.
Replace the fuel pressure regulator.
There is a sudden sharp drop of
the fuel pressure immediately
after the engine is stopped.The check valve (within the fuelpump) is not closed.Replace the fuel pump.
(15)Remove all remaining pressure from inside the fuel pipe.(16)Disconnect the fuel pressure gauge and the special tool
from the delivery pipe.
CautionBecause there will be.a slight amount of remaining
pressure in the fuel pipe line, use rags to cover so thatfuel doesn’t splatter.
(17)Replace the O-ring at the end of the fuel high-pressure hose
with a new one.(I 8)After connecting the fuel high-pressure hose to the delivery
pipe, tighten the installation bolt at the specified torque.
dTightening torque: 5.0 Nm (3.6 ftlbs.)
(19)Check to be sure that there is no fuel leakage.@ Apply battery voltage to the terminal for activation of
the fuel pump so as to activate the fuel pump.@ With fuel pressure applied, check for leakage of the fuel
line.
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13-142FUEL SYSTEM - Injector
SERVICE POINT OF REMOVAL
MlBSSAI1. DISCONNECTION OF HIGH PRESSURE FUEL HOSE
Bleed the residual pressure within the fuel pipe line so as to
LA;prevent the flow of fuel.
Caution
Cover the hose connection with rags to prevent splash
of fuel that could be caused by some residual pressurein the fuel pipe line.
INSPECTION
INJECTORS
M13SCAC(1) Measure resistance between terminals of injector using a
circuit tester.
Standard value:13
- 16 R [at 20°C (68”F)]
2
- 3 LR [at 20°C (68”F)l
(2) If the resistance is out of specification, replace the injector.
SERVICE POINTS OF INSTALLATION
MlBSDAV
10. INSTALLATION OF INJECTORWhile turning the injector to the left and right, install it to the
delivery pipe.
Check to be sure that the injector turns smoothly.
LCaution
If it does not turn smoothly, the O-ring may be trapped.Remove the injector and then
m-insert it into the
delivery pipe and check once again.
4. INSTALLATION OF FUEL PRESSURE REGULATORWhen connecting the fuel pressure regulator to the delivery
pipe, apply light oil or petrol to the O-ring, and then insert,
being careful not to damage the O-ring.
1. CONNECTION OF HIGH PRESSURE FUEL HOSE
When connecting the high pressure fuel hose to the
delivery pipe, apply petrol to the hose union, and then
insert, being careful not to damage the O-ring.
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FUEL SYSTEM - Fuel Tank13-147
Rubber hose
ngn
03FOOl
9
OSFOOB
05FOO7SERVICE POINT OF REMOVAL
MlBGBAK
12. DISCONNECTION OF HIGH PRESSURE FUEL HOSEDisconnect the hose from body main pipe first and then
from fuel pump.
Caution
Cover the hose connection with rags to prevent splash
of fuel that could be caused by some residual pressurein the fuel pipe line.
INSPECTION
MlBGCAMl Check the hoses and the pipes for crack or damage.
l Check the fuel tank cap for malfunction.
l Check the fuel tank for deformation, corrosion or crack.
l Check the fuel tank for dust or foreign material.
NOTEIf the inside of the fuel tank is to be cleaned, use any one of
the following:
(1) Kerosene
(2) Trichloroethylene
(3) A neutral emulsion type detergent
OVERFILL LIMITER (TWO-WAY VALVE)Connect a clean rubber hose to the overfill limiter and check for
operation.
Inspection procedureLightly blow from the inlet
(fuel tank) sideNormal conditionAir passes through after a
slight resistanceLightly blow from the outletAir passes through
(canister) sideISERVICE POINTS OF INSTALLATION
MlSGDAT19. INSTALLATION OF FUEL PUMP AND FUEL GAUGE
UNIT ASSEMBLY
Align the three positioning projections of the packing with
the holes in the fuel pump and fuel gauge unit assembly.
TSB Revision18.13. IO. 7. CONNECTION OF VAPOR HOSE
(1) If the pipe has a stepped part, connect the vapor hose
to the pipe securely, up to the stepped part, as shown in
the illustration.
(2) If the pipe does not have a stepped part, connect the
vapor hose to the pipe securely, so that it is the
standard value.
Standard value: 25
- 30 mm (1.0 - I.2 in.)

13-150FUEL SYSTEMFuel Pump and Fuel Gauge Unit Assembly- and Overfill Limiter (Two-Way Valve)
Rubber hose
9Flare nut
Secure side
03Yo43Camst
ide
DO304INSPECTION
MlBUCAB
OVERFILL LIMITER (TWO-WAY VALVE)~
Connect a clean rubber hose to the overfill limiter and check for
operation.
‘d
Inspection procedureNormal conditionLightly blow from the inlet
(fuel tank) sideAir passes through after a
slight resistanceLightly blow from the outlet
(canister) sideAir passes through
SERVICE POINTS OF INSTALLATION
M13UDAC6. INSTALLATION OF FUEL PUMP AND FUEL GAUGE
UNIT ASSEMBLY
Align the three positioning projections of the packing with
the holes in the fuel pump and fuel gauge unit assembly.
5. 4. CONNECTION OF HIGH PRESSURE FUEL HOSE
Temporarily tighten the flare nut by hand, and then tighten it
to the specified torque, being careful that the high pressure
fuel hose does not become twisted.
CautionWhen tightening flare nut, be careful not to bend or
[J’twist line to prevent fuel pump from damage.\3. INSTALLATION OF OVERFILL LIMITER (TWO-WAY
VALVE)Install so that the overfill limiter is facing in the direction
shown in the illustration.
1. INSTALLATION OF FUEL GAUGE COVER
Before installing the fuel gauge cover, apply the specified
sealant to the rear floor pan.
Specified sealant: 3M ATD Part No. 8509 or equivalent
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13-156ENGINE CONTROL - Service Adjustment Procedures
SERVICE ADJUSTMENT PROCEDURES
M13FBCKIACCELERATOR CABLE INSPECTION AND
a ’ADJUSTMENT
For models equipped with the cruise control system, refer to
P. 13-l 58.(1) Turn air conditioner and lights OFF.
Inspect and adjust at no load.
(2) Warm engine until stabilized at idle.
(3) Confirm idle speed is at prescribed rpm.
(4) Stop engine (ignition switch OFF).
(5) Confirm there are no sharp bends in accelerator cable.
(6) Check inner cable for correct slack.
(7) If there is too ‘much slack or no slack, adjust play by the
following procedures.@ Turn the ignition switch to the ON position (without
starting the engine) and leave in that condition for
approximately 15 seconds.@Loosen the adjusting bolts on the air intake plenum, and
then secure the outer cable so that the free play of
th,einner cable will be the standard value.
Standard value:
1 - 2 mm (.04 - .08 in.)3-5 mm
(.12-.20 in.)
NOTE
\JIf there is excessive play of the accelerator cable, the
vehicle speed drop (“undershoot”) when climbing a slope
will be large.
If there is no play (excessive tension) of the accelerator
cable, the idling speed will increase.
(8) After adjusting, confirm that throttle valve fully opens and
closes by operating pedal.
(9) Adjust accelerator cable play and confirm throttle lever
stopper touches the fixed SAS.
ACCELERATOR SWITCH INSPECTION AND
A
nADJUSTMENTMlBFlBC
09FO117Make sure that when the accelerator pedal is free, there is
;$ustingcontinuity between the terminals of the accelerator switch and
/that when the pedal is pressed until the indicated pedal stroke
A reaches the standard value, there is no continuity between
the terminals of the switch.
Standard value:Accelerator switch switching point
2 - 6 mm (.079 - .24 in.)If stroke A is out of specification, adjust with adjusting bolt.
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