1989 MITSUBISHI GALANT light

FUEL SYSTEM - Service Adjustment Procedures13-245
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SERVICE ADJUSTMENT PROCEDURES
CURB IDLE SPEED INSPECTION
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(1) The vehicle should be prepared as follows before the inspection.
l Engine coolant temperature:
85-95°C (185-205°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: Neutral
(P for vehicles with an automatic
transaxle)
(2) Connect a tachometer.
NOTE
1. Refer to P.13-246 for information concerning connec-
tion of a tachometer.
2. For tachometer, one-half of the actual engine rpm is
indicated, so the actual engine rpm in two times the
indicated value shown by the tachometer. models>
(3) Set a timing light in position.
(4) Ground the terminal for adjustment of ignition timing.
(5) Start the engine and let it idle.
(6) Check whether or not the ignition timing
is the standard
value; if not, adjust.
Standard value:
5”BTDC f 2”
(7) Stop grounding the terminal for adjustment of ignition timing.
(8) Let the engine idle for two minutes.
(9) Check the idling rpm.
Curb idle speed:
75Ok 100 rpm
800+ 100 rpm
NOTE
The idling rpm is automatically regulated by the idle airsystem.
(10)lf not within the standard value range, refer to the CHECK
CHART CLASSIFIED BY PROBLEM SYMPTOMS and
check the
MFI component.
BASIC IDLE SPEED ADJUSTMENT
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NOTE
1. The standard idling speed has been adjusted, by the en- gine speed adjusting screw (RPM adjusting screw), by the
manufacturer, and there should usually be no need for
readjustment.
2. Use the following procedure to adjust when the idling speed drops due to an incorrect adjustment, high idling
speed, or when a load such as the air conditioning is ap-
plied on the engine.
3. The adjustment, if made, should be made after first con- firming that the spark plugs, the injectors, the idle air con-trol motor, the compression pressure, etc. are all
normal.~~-
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13-246FUEL SYSTEM - Sewice Adjustment Procedures
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(1) The vehicle should be prepared as follows before the
inspection and adjustment.
l Engine coolant temperature:
85-95°C (185-205°F)
l Lights, electric cooling fan and accessories: OFF l Transaxle: Neutral (P for vehicles with an automatic transaxle)
(2) Connect the scan tool to the data link connector (white).
NOTE
When the scan tool is connected, the diagnostic test mode
control terminal is grounded.
(3) If the scan tool is not used, follow the steps below.
@ Insert a paper clip (from the harness side) into the l-pin connector shown in the figure at the left.
Take care not to disconnect the connector.
/ Paper chp -
f!f--i!t
Ah
-II
For a female pin
For a male
ptn (Insert
at side (Insert
at
lock tab side.
opposite from
lock
tab.)OlL0246
Caution
The paper clip should be inserted between the termin-
als as shown in the figure at the left. @ Connect a primary-voltage-detection type of
tacho-
meter to the paper clip.
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13-248FUEL SYSTEM - Service Adjustment Procedures
(8) Switch OFF the ignition switch.
(9) If the scan tool was not used, disconnect the jumper wire from the diagnostic test mode control terminal. (10)Disconnect
the jumper wire from the terminal for adjust-
ment of ignition timing, and return the connector to its
original condition.
(11
)Start the engine again and let it run at idle speed for about
ten minutes; check to be sure that the idling condition is
normal.
THROTTLE BODY (THROTTLE VALVE AREA)
CLEANING
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(1) Start the engine and warm it up until the temperature of the engine coolant reaches
80°C (176°F) or higher; then stop
the engine.
(2) Disconnect the air intake hose at the throttle body side.
(3) Plug the bypass passage entrance of the throttle body.
Caution
Be absolutely sure that no cleaning liquid enters the
bypass passage.
(4) Spray cleaning liquid (from the intake port of the throttle body) onto the valve, and then leave as is for about five
minutes.
(5) Start the engine and race it a few times; then let it run at
idle speed for about one minute.
NOTE
If, because the bypass passage is plugged, the engine
idling speed is unstable (or the engine stalls), let the engine
run with the throttle valve slightly open.
(6) If deposits are not removed from the throttle valve, repeat steps (4) and (5).
(7) Remove the plug from the bypass passage entrance.
(8) Connect the air intake hose.
(9) Using the scan tool, erase the diagnostic trouble code, or disconnect the battery’s ground cable for ten seconds or
longer and then reconnect it. (lO)Adjust
the basic idle speed (engine speed adjusting screw).
(Refer to
P.13-245.)
THROTTLE POSITION SENSOR ADJUSTMEyTmEE
(1)Connect the scan tool to the data link connector (white).
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13-262FUEL SYSTEM - On-Vehicle Inspection of MFI Components
INSPECTION
Using Scan tool
1 Data 12reading
L
Data displayInspection conditions
Sensor de-. Engine coolanttection airtemperature: 85-95°Cvolume (fre-(185-205°F)quency) .Lights, cooling fan, elec-trical accessories: OFF. Transaxle: neutral (PJTmodels: “P” range)
Engine condition
Idling
2,000 rpm
Racing
Standard value 25-50
Hz 30-50 Hz
60-90 Hz 50-80 Hz
Frequency increases as
racing rpm increases.
NOTEThe volume air flow sensor output frequency may be about 10% higher than\
indicated above when the vehicle is new
[driven approximately 500 km(300 miles) or less].
i
Regular waveform03AO203
HARNESS INSPECTION Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the osilloscope
pick-up point as
shown in the circuit diagram, and check the wave form.
Measure the terminal voltage.
. Connector: Disconnected
. Ignition switch: ON
connectorOlMaa
Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
Harness side
connectorthe multiport fueinjection relay.
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FUEL SYSTEM - On-Vehicle Inspection of MFI Components13-275
INSPECTION
Using Scan tool
Function
Item No.
Data reading 26
Data displayInspection conditions Throttle valveNormal indication
Switch statusIgnition switch: ONTo idle positionON(Check after pumpingaccelerator several times.)
Slightly openedOFF
HARNESS INSPECTION
71
-
Harness side
Measure the power supply voltage of
the closed throttle position switch.
-. Connector: Disconnected
. Ignition switch: ON
1Voltage (VI
4 or more
ASTOP
Repair theharness.
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ISENSOR INSPECTION
I(1) Disconnect the throttle position senso_r connector
(2) Check the continuity between terminal QI and body ground.
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Accelerator pedal Continuity
DepressedNon-conductive (m S2)
ReleasedConductive (0 52)
(3) If out of specification, replace the throttle position sensor
assembly.

13-296FUEL SYSTEM -On-Vehicle
Inspection
of
MFI
Components
INSPECTION
Using Scan tool
Function Item No. Data displayInspection conditionsEngine coolant temperature Standard value1
Data 41;ctJ$onEngine crankingAt 0°C (32”F)*2Approx. 17 ms
readingApprox. 40 ms
At 20°C (68°F)Approx. 38 ms
Approx. 19 ms
At 80°C (176°F)Approx. 9 ms
Approx. 4.5 ms
Function
Datareading
3TE Item No.
41
Data display
$ctX$on
Inspection conditionsEngine condition
Standard value
. Engine coolant tempera-Idling2.4-3.2 ms
ture:1.6-2.6 ms 85-95°C
(185-205°F)
. Lights, cooling fan, electric- 2,000 rpm1.9-2.9
ms
al accessories: OFF1.4-2.2 ms . Transaxle: neutralDuring sudden Increasesracing
+l:The injector activation time indicates the time under the following cond\
itions: a power source voltage of 11V and acranking rpm of 250 rpm or less.*2: Simultaneous injection at four cylinders when engine coolant temperatur\
e is 0°C (32°F).*3: The injector activation time may be about 10% longer than indicated abo\
ve when the vehicle is new [driven
approximately 500 km (300 miles) or less].
Function Item No.Description Inspection conditionsNormal indication
Actuator test 01No. 1 injector is shut off.
Engine: idling after warmThe idling condition
02No. 2 injector is shut off.?!hut off the injectors inchanges more.
(Either becomes more un-
03
No. 3 injector is shut off.
04
No.4 injector is shut off.
sequence during after
engine warm-up, check
the idling condition.) stable, or engine stalls.)
,d&- A: InjectorNormal wavetormdrive time
HARNESS INSPECTION

@ Harness sideconnector
I
L
Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the oscilloscope pick-up point as
shown in the circuit diagram, and check the waveform at
the drive side of each injector.
Measure the power supply voltage ofthe resistor.
. Connector: Disconnected. Ignition switch: ON
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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
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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
lnsoection
of MFI
ComDonents13-301
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Idle aircontrol motor
10 /(stepper motor)
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Operational Check
(1) Remove the throttle body.
(2) Remove the stepper motor
(3) Connect the special tool (Test harness) to the idle air con- trol motor connector.
(4) Connect the positive (+) terminal of a power supply
(approx. 6
V) to the white clip and the green clip.
(5) With the idle air control motor as shown in the illustration, connect the negative (-)
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 a result of
the activation of the stepper motor. @ Connect the negative
(-) terminal of the power supply
to the red and black clip.
@ Connect the negative (-) terminal of the power supply
to the blue and black clip. @ Connect the negative
(-) terminal of the power supply
to the blue and yellow clip.
@I Connect the negative (-) terminal of the power supply
to the red and yellow clip. @ Connect the negative
(-) terminal of the power supply
to the red and black clip. @ Repeat the tests in sequence from (5) to
(1).
(6) If, as a result of these tests, vibration is detected, the
stepper motor can be considered to be normal.
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