check engine MITSUBISHI GALANT 1989 Service Repair Manual

FUEL SYSTEM - On-Vehicle
inspection
of MFI
Components13-297
@I Harness sideconnector
Measure the power supply voltage of
the injector.
. Resistor connector: Connected
. Injector connector: Disconnected
. Ignition switch: ON
module harness
side connecror
ACTUATOR INSPECTION
INJECTOR
CHECKING OPERATION SOUND
Using a sound scope, check the operation sound (“chi-chi-chi”)
of injectors during idling or during cranking.
Check that as the rotating speed increases, the frequency of
the operating sound also increases.
Caution
Note that even if the injector you are checking is not
operating, you will hear the operating sound of the other
injectors.
NOTE
If no operating sound is heard from the injector that is being
checked, check the injector drive circuit. If there is nothing
wrong with the circuit, a defective injector or engine control module is suspected.
MEASURING RESISTANCE BETWEEN TERMINALS
(1) Remove the injector connector.
(2) Measure the resistance between the terminals.
Standard value:
13-16 Sz [at 20°C (68”F)I
2-3
Q [at 20°C (68”F)] >
(3) Install the injector connector.
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FUEL SYSTEM -On-Vehicle Inspection of
MFI Components13-299
OPERATION
l The amount of air taken in during idling is
regulated by the opening and closing of the
servo valve located in the air passage that
bypasses the throttle valve.
l The servo valve is opened or closed by the
activation of the stepper motor (incorporated
within the idle air control motor) in the forward
or reverse direction.
TROUBLESHOOTING HINTS
Hint 1: If the number of stepper motor steps increases to
IOO- 120 steps or decreases
to 0 step, the cause may be presumed to be a malfunction of the stepper motor or
damaged or disconnected wiring of the
harness.
Hint 2: If the number of stepper motor steps
deviates from the standard value even
though the results of the checking of the
harness of the idle air control motor and of
the comoonent
itself indicate no abnormal
condition, the cause may be presumed to be one of the following.
INSPECTION
Using Scan tool
lBattery power supply is supplied, by way of the
multiport fuel injection relay, to the coil of the
stepper motor. The engine control module
switches ON the power transistors (located
within the engine control module) in sequential
order, and, when current flows to the stepper motor coil, the stepper motor is activated in the
forward or reverse direction.
(1) Improper adjustment of the standard
idling speed.
(2) Deposits adhered to the throttle valve.
(3) Leakage of air into the intake manifold
from a gasket gap, etc.
(4) Incomplete close contact of the EGRvalve seat.
(5) Incomplete combustion within the
cylinder.
(Malfunction of the spark plugs, the
ignition coil, the iniectors,
the
com- pression
pressure, etc.)
FunctionItem No.Data display Check conditions Load conditionsStandard value
Data reading 45Steppermotor steps. Engine coolant tempera-
. Air conditioning
4-14Step
ture:switch: OFF 85-95°C

(185-205°F)
. Lights, electrical cooling
:$b::pfan and accessories: OFF
. Transaxle: neutral
. Closed throttle switch: ON
- Air conditioning 20-60 Step
switch: ON
(The compressor clutchshould be activated when
the air conditioning switch;J-;;o~P
is switched ON.)* Engine: idling
1;:!,1;:!,
/!-I\/!-I\
f$&$:”f$&$:”
! ,‘,! ,‘,
4);4);
;jj\(Q(j!jGZ-);jj\(Q(j!jGZ-)
lili
q#Q~Hq#Q~HF]F]
ii 2 L J 2 L ~ -0SClllO 4ii 2 L J 2 L ~ -0SClllO 4
NOTE
When the vehicle is new (driven approximately 500 km (300 miles) or l\
ess) the number of steps may be about
30 steps greater than the standard value indicated above.
Using Oscilloscope
(1) Connect the probe to each oscilloscope pick-up point as
shown in the circuit diagram.
(2) Start the engine.
(3) When the air conditioning switch is turned on, the idling speed increases to operate the idle air control. Check theinstantaneous waveform.
NOTE
Keep in mind that the waveform can be observed only
when idle air control is in operation.

FUEL SYSTEM - On-Vehicle Inspection
of
MFI Components
HARNESS INSPECTION
connector
@ Harness side7
connectorharnessside connw&
cI
7FUOOlO
Measure the power supply VOltage ofthe idle air control motor.
. e Idle air control motor connec-tor: Disconnected. Ignition switch: ON
Check for an open-circuit, or a short-circuit to ground, between the enginecontrol module and idle air controlmotor.
. Engine control module connec-tor: Disconnected* Idle air control motor connec-‘--R&heharness.tor: Disconnected
ACTUATOR INSPECTION
Checking the Operation Sound
(1) Check that the operation sound of the stepper motor can
be heard after the ignition is switched ON (but without
starting the motor).
(2) If the operation sound cannot be heard, check the stepper
motor’s activation circuit.If the circuit is normal, it is probable that there is a
malfunction of the stepper motor or of the engine control
module.
Checking the Coil Resistance
(1) Disconnect the idle air control motor connector and con- nect the special tool (Test harness).
(2) Measure the resistance between terminal
@ (white clip of
the special tool) and either terminal
@ (red clip) or terminal
$d;!lue clip) of the connector at the idle air control motor
Standard value: 28-33 &
at
20°C (68°F)
(3) Measure the resistance between terminal @ (green clip of
the special tool) and either terminal
@ (yellow clip) or ter-
minal
@ (black clip) of the connector at the idle air control
motor side.
Standard value: 28-33
51 at 20°C (68°F)
J
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r
FUEL SYSTEM -On-Vehicle Inspection
of
MFI Components13-303
INSPECTION
Using Scan tool
Function Item No.
Data reading 44
Data displayInspection conditionsEngine condition Standard value
Ignition
advance
. Engine: warm
. Timing light: set750 rpm (idling)5-15” BTDC
(Use the timing light to
check the actual ignition 2,000 rpm32 - 4 1 “BTDCtiming.)
Oscillo 1
Normal waveform
Oscilio 2
!
1ov --
-
ovNormal waveform
HARNESS INSPECTION
Harness side
connectorE 0-0
J
El0
connectorI
lEnginecontrol
module
harness
sideconnector
Using Oscilloscope
1. Primary signal of ignition coil
(1) 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 ignition power transistor
(3) Connect the probe to oscilloscope pick-up point 2 as
shown in the circuit diagram, and check the control
signal of the ignition power transistor.
Measure the power supply voltage ofthe ignition coil.
. Connector: Disconnected. Ignition switch: ON
Voltage (VI
IBattery positive voltageIIIgnitionswitch)
Check for an open-circuit, or a
short-circuit to ground, between the engine
control module and the ignition coil.
* Engine control module connec- tor: Disconnected
* Ignition coil connector: Discon-nected
i
Repair theharness.
N23l3k-m)
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13-306FUEL SYSTEM - On-Vehicle
Inspection
of
MFI
Components
Harnesscirio
-.-.,@ connector
Measure the power supply voltage ofthe ignition coil.
. Connector: Disconnected. Ignition switch: ON
HARNESS INSPECTION
Harness side
I
Measure the power supply voltage ofthe ignition coil.
. Connector: Disconnected. ignition switch: ON
control module and the ignition
power transistor.
. Engine control module connec-tor: Disconnected. Ignition power transistor connec-tor: DisconnectedRepair theharness.
KI3zil-m)
6FU1387I
t III1an open-circuit, or a short-ground, between the igni-
power transistor and the ignition
coil connector: Discon-
* Ignition power transistor connec-tor: DisconnectedReoair the
t
hamess.
KBEI-GUI~GZWBXZl)
IJ
5
Harness side@ connector
J
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Check for continuity of the groundcircuit.
. Connector: Disconnected

13-308FUEL SYSTEM - On-Vehicle Inspection
of
MFI
Components
OPERATION
l
The fuel pressure solenoid is an ON-OFF type of
solenoid valve and changes pressure fed into
the fuel pressure regulator to intake manifold
pressure and barometric pressure.
l Battery power is supplied to the fuel pressure
solenoid via the multiport
fuel injection relay.
When the engine control module turns on the
power transistor in the unit, current flows in the
coil and barometric pressure is fed to the fuel pressure regulator.
INSPECTION
Using Scan tool
0 If engine coolant temperature (approximatel
y
95°C (203°F) or more) and also air intake
temperature (approximately
50°C (122°F) or
more) are high when the engine is started, fuel
pressure is controlled in order to maintain
pressure at approximately 260
kPa (37 psi)
immediately after starting and then, after a lapse
of approximately 30 seconds to 2 minutes, to lower it to approximately 190
kPa (27 psi).
Function Item No.
Actuator test 09
DescriptionInspection conditionsNormal condition
$$;;i;;;alve switched fromIgnition switch: ONOperating sound is
heard when driven.
HARNESS INSPECTION
Harness side
Measure the power supply VokW 1
. Connector: Disconnected 1
. Ignition switch: ON
Voltage 04
1 Battery positive voltage 1t)lt<
02
Repair theharness.
@I4,MFI
Engine control module
harness side connecto
Harness side
Check for an open-circuit, or shot-t-circuit to ground, between the fuel
pressure solenoid and the engine
control module.
- Engine control module connec-tor: Disconnected. Fuel pressure solenoid connec-tor: DisconnectedRepair theharness.
h25xwzl21,
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FUEL SYSTEM -On-Vehicle
Inspection
of
MFI Components13-309
ACTUATOR INSPECTION
Operation inspection
NOTE
When removing the vacuum hose, make a mark so that it can
later be installed in the original connecting position.
(1) Remove the vacuum hose (blue stripe, black) from the solenoid valve.
(2) Cut off the harness connector.
(3) Apply a negative pressure in the nipple to which the black vacuum hose is connected with a hand vacuum pump and
check that it is airtight when voltage is applied to the
solenoid valve terminal and when not applied.
Battery Other solenoid Normal conditionvoltagevalve nipple
Not applied OpenVacuum leaks.
Closed by fingerVacuum is maintained.
Applied
OpenVacuum is maintained.
Inspection of coil resistance
Measure coil resistance with a tester.
Standard value: 36-46
S2 [at 20°C (68”F)I
TURBOCHARGER WASTE GATE SOLENOID
Multiport fuelinjection relay
@Component side,,2
connector/\
1
lE?l283
@J Harness side\/
connector“1
II
Engine control module connector
MlJZABA
Turbocharger wastegate solenoid
Engine
control
1module105
1
OlLo8381I
0110324
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13-310FUEL SYSTEM - On-Vehicle Inspection
of MFI Components
OPERATION
lThe turbocharger waste gate solenoid is an ON-tion relay. When the engine control
module
OFF type solenoid valve and controls the leaking turns on the power transistor inside
the unit,
of overboost pressure that is fed to the
turbo-current flows to the coil and some overboost
charger waste gate actuator. pressure that is fed to the turbocharger waste
l Battery power is supplied to the turbocharger gate solenoid leaks out.
waste gate solenoid via the
multiport fuel injec-
TROUBLESHOOTING HINTS
Since the results of the inspection of the turbo-
charger waste gate solenoid harness and single
parts are normal, the following troubles can be in-
ferred if there is some trouble such as poor accele-
ration, etc.
(1) Malfunction of the overboost pressure control system
(2) Poor intake air hose connection
(3) Malfunction of turbo charger, turbocharger waste gate solenoid
(4) Clogging of exhaust gas system
INSPECTION
Using Scan tool
Function Item No.
Actuator test 12
Description Inspection conditionsNormal condition
Sp:$r?,oi$;;alve switched from
ignition switch: ONOperating sound is
heard when driven.
HARNESS INSPECTION
Harness sideconnector
1
@
uI 6FU1305
Engine
control
module
harness
side
connector
105
JP--r6FUO973
Measure the power supply voltage.
9
1 Battery positivevoltage ]c)ll< f k&f$i
Check for an open-circuit, or short-circuit to around, between the turbn-charger w’aste g&e solenoid and thkengine control module.
* Turbocharger waste gate solenoid
connector: Disconnected
* Engine control module connec-tor: DisconnectedRepair theharness.
C@O--rn)
ACTUATOR INSPECTION
Refer to GROUP 15.
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FUEL SYSTEM -
On-Vehicle
Inspection
of MFI
Components13-311
BOOST METER
meter/
Ignition switch (IG,)I
M13ZACA
Boost meter
Engine control module connector OlLO838
A6FU1552
HARNESS INSPECTION
@ Harness sideconnector
6FU1550
Engine
control module
harness
side
connectc
ii+7 =6FU1551
Measure the power supply voltage.
. Connector: Disconnected. Ignition switch: ON
Voltage (VI
1Battery positive voltage 1
cl2
Repair theharness.
@~,“”
Check for an open-circuit or a short-circuit to ground, between the enginecontrol module and the boost meter.
* Booste meter connector: Discon-nected* Engine control module connec-tor: Disconnected
4.ASTOP
i+
Repair theharness.
vAlB-[33)

13-312FUEL SYSTEM - On-Vehicle Inspection
of
MFI
Components
FUEL PRESSURE TESTMxwXAAe
(1) Reduce the internal pressure of the fuel pipes and hoses.
(2) Disconnect the fuel high pressure hose at the fuel rail side.
Caution
Cover the hose connection with rags to prevent splash
of fuel that could be caused by some residual pressure
in the fuel pipe line.
(3) Remove the throttle body stay.
(4) Place the MD998742-01
adapter on the end of the fuel rail,
then attach the fuel high pressure hose to the adapter
using the bolts supplied with the MIT210196
fuel pressure
test assembly.
(5) Attach one end of the fuel hose supplied with the
MIT21 0196 to the quick-disconnect fitting on the
MD998742-01 adapter. Attach the other end of the hose
to the fuel pressure gauge.
(6) Connect the (-) battery terminal.
(7) Connect a jumper wire to the terminal for activation of the fuel pump and to the positive
(+) terminal of the battery to
activate the fuel pump. With fuel pressure applied, check to
be sure that there is no fuel leakage from the fuel pressure
gauge and the special tool connection part.
(8) Disconnect the jumper wire (from the terminal for activa-
tion of the fuel pump) to stop the fuel pump.
(9) Start the engine and let it idle. (10)Measure
the fuel pressure during idling.
Standard value:
Approx. 270 kPa (38 psi)
Approx. 190
kPa (27 psi)
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