1991 MITSUBISHI 3000GT Service Manual

FUEL SYSTEM - On-vehicle Inspection of MPI Components13-119PURGE CONTROL SOLENOID VALVE
Q Harness side
connector
I
Control relay
@ Equipment side
connector connector
unit
OlAO324
Engine control unit connector
7FUO653OPERATION
lThe purge control solenoid valve is an ON-OFF type one which controls introduction of purge air from the
canister into the intake air plenum.
lThe battery power is supplied to the purge control solenoid valve through the control relay. When the
engine control unit turns ON the power transistor in the unit, current flows to the coil, introducing purge
air.
INSPECTION
Using Multi-use Tester
Function
Actuator testItem No.Drive content
Check conditionNormal state
08Solenoid valve from OFFIgnition switch: ONOperating sound is heard
to ONwhen driven
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13-120FUEL SYSTEM - On-vehicle Inspection of MPI Components
HARNESS INSPECTION
@ Harness side
connector
T7FUO525
I -connector57FUO526
1
Measure the power supply voltage.
l Connector: Disconnected0 Ignition switch: ON
Check for an open-circuit, or a short-circuit to ground between the purgecontrol solenoid valve and the engine
control unit,
lEngine control unit connector:
Disconnected@-+A
lPurge control solenoid valve con-nector: DisconnectedRepair the
harness.

ACTUATOR INSPECTIONRefer to GROUP 17
- Evaporative Emission Control System.
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FUEL SYSTEM - On-vehicle lnwection of MPI ComDonents13-121
LEGR CONTROL SOLENOID VALVE - Non Turbo, Turbo>MlBYZBAControl relav
EGR control
solenoid valve@ Equipment side
connector
Engine
control
unitEngine control unit connector
7FUO653
OPERATION
lThe EGR control solenoid valve is a duty control type solenoid valve. It makes control by leaking EGR valve
operating negative pressure to the throttle body A port.
lPower supply from the battery is sent through the control relay to the EGR control solenoid valve. When
the engine control unit turns off the power transistor inside the unit, current no more flows through the
coil and EGR valve operating negative pressure leaks.
TROUBLESHOOTING HINTIf the results of EGR control solenoid valve on-vehicle and off-vehicle inspections are normal but the
self-diagnosis code for EGR system failure is displayed, check the EGR valve, vacuum hose and EGR passage
for blocking.
c.
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13-122FUEL SYSTEM - On-vehicle Inspection of MPI Components
INSPECTIONUsing Multi-use Tester
Function
Actuator testItem No.
Drive content
Check condition
Normal state
10Change solenoid valve
from OFF to ON stateIgnition switch: ONOperating sound is heardwhen driven
HARNESS INSPECTION
1
@ Harness side
connector
Measure the power supply voltage.
Y01105*4Engine control unit
harness side connector
Control relay)
Repair the
-S harness.C@vJ-~)
d
Ls
ACTUATOR INSPECTIONRefer to GROUP 17
- Exhaust Gas Recirculation (EGR) System.
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FUEL SYSTEM - On-vehicle Inspection of MPI ComDonents13-123FUEL PRESSURE CONTROL VALVE
Control relay
Fuel pressure
control valveEquipment
connectorside
Enaine control unit
connector
7FUO653
OPERATION
lThe fuel pressure control valve is an ON-OFF type solenoid valve that switches the pressure introduced to
the fuel pressure regulator between either intake manifold pressure or barometric pressure.
lBattery power is supplied to this valve via the control relay. When the engine control unit turns ON the
internal power transistor, the coil is energized to allow barometric pressure to be introduced to the fuel
pressure regulator.
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13-124FUEL SYSTEM -On-vehicle Inspection of MPI Components
INSPECTIONUsing Multi-use tester
Function
Actuator testItem No.Drive content
Check conditionNormal state
09Turn solenoid valve fromIgnition switch: ONOFF to ONr%;reard when
HARNESS INSPECTION
@ Harness side
connector
Measure the power supply voltage.
l Connector: Disconnectedl Ignition switch: ON
Voltage
(V)2-* q
SVRepair thei* harness.(@m - Con-
trol relay)
7FUO527
Check for an open-circuit, or a short-circuit to ground, between the fuelpressure control solenoid valve andthe engine control unit.
lEngine controLunit connector:
Disconnected
lFuel pressure control valve con-nector: Disconnected
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FUEL SYSTEM - On-vehicle Inspection of MPI Components13-125
ACTUATOR INSPECTION
Operation Check
NOTEBefore disconnecting the vacuum hose, mark it to ensure
reconnection at the correct position.
(1) Remove the vacuum hose (blue stripe on black) from the
solenoid valve.
(2) Disconnect the harness connector.
(3) Apply a negative pressure to the nipple to which the black
vacuum hose has been connected and check air-tightness
with and without the battery voltage applied to the solenoid
valve terminal.
BatteryvoltageThe other nipple
of solenoid valveNormal state
Not applied
qj
I
AppliedOpenNegative pressure isheld
Coil Resistance Check
(I) Measure the coil resistance with a circuit tester.
Standard value: 36
- 46 R [at 20°C (68”F)]
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13-126FUEL SYSTEM - On-vehicle Inspection of MPI Components
WASTE GATE CONTROL SOLENOID VALVE

7FU1007Control relav
Waste gate control
solenoid valve
Q Equipment side
connector
unit
0110324Enqlne control unit connector
7FUO653
OPERATIONlThe waste gate control solenoid valve is an ON-OFF type solenoid valve that controls the boost pressure
that is introduced to the waste gate actuator.
lBattery power is supplied to this valve via the control relay. When the engine control unit turns ON the
internal power transistor, the coil is energized to release part of the boost pressure applied to the waste
gate actuator.
TROUBLESHOOTING HINTSIf the waste gate control solenoid valve harness and the unit itself are normal, but poor acceleration or other
abnormalities are experienced, the
follwing problems are suspected.
(1) Faulty boost pressure control system
(2) Poor connection of intake air hose
(3) Faulty turbocharger or waste gate actuator
(4) Clogged exhaust system
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