1989 MITSUBISHI GALANT light

13-32
FUEL SYSTEM - Troubleshooting/Service Adjustment Procedures
FUEL TANK AND FUEL LINEMlBEAAA
Symptom Probable cause Remedy
Engtne malfunctions
Bent or kinked fuel pipe or hose Repair or replace3ue to insufficient fuel
SUPPlYClogged fuel pipe or hoseClean or replace
Clogged fuel filter or in-tank fuel filter Replace
Water in fuel filter Replace the fuel filter or clean the fuel tank
and fuel line
Dirty or rusted fuel tank interior Malfunctioning fuel pump
(Clogged filter in the pump) Clean or replace
Replace
Evaporative emission Mispiping of vapor line
Correct
control system malfunc-
tions (When fuel tank Disconnect vapor line piping joint Correct
filler tube cap is re- moved, pressure releas-
Folded, bent, cracked or clogged vapor line Replace
ng noise is heard) Faulty fuel tank filler tube cap
Malfunctioning fuel tank pressure control
valve Replace
Replace
LL
m ~~ : Paper clip-
F l!;“I /yFp- -
izd--_7-01
A0086SERVICE ADJUSTMENT PROCEDURES
CURB IDLE SPEED INSPECTION
MlBFHAFt
(1) The vehicle should be prepared as follows before the inspection.
lEngine coolant temperature: 85-95°C (185-203°F)
l Lights, electric cooling fan and accessories: OFF
l Transaxle: Neutral
(P for vehicles with an automatic
transaxle)
(2) Connect a tachometer or connect the scan tool to the data
link connector.
NOTE
Refer to
P.13-33 for information concerning connection Of
a tachometer.
(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 + 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:
7502 100 rpm
NOTE
The idling rpm is automatically regulated by the idle-speed control system.
1
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FUEL SYSTEM -Service Adjustment Procedures 13-33
For a female
pin
For a male pin
(insert at side (Insert at lock tab side.,
opposite from lock tab.)
OlLO246
(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
MlBFHBA
(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) Slacken the accelerator cable enough.
(3) Connect the scan tool to the data link connector (white).
(4) If the scan tool is not used, follow the steps below.
@I 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.
Caution
The paper clip should be inserted between the
terminals 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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FUEL SYSTEM -Service Adjustment Procedures 13-35
(14)Adjust the play of the accelerator cable. (Refer to P.13-
329.)
(15)Connect the idle-speed control motor’s connector.
(16)Adjust the throttle-position sensor.
(17)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
MllFlCK
(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) Spray cleaning liquid (from the intake port of the throttle body) onto the valve, and then leave as is for about fiveminutes.
(4) Start the engine and race it a few times; then let it run at idle speed for about one minute.
NOTE
If the engine idling speed is unstable (or the engine stalls),
let the engine run with the throttle valve slightly open.
(5) If deposits are not removed from the throttle valve, repeat steps (3) and (4).
(6) Connect the air intake hose.
(7) Using the scan tool, erase the diagnostic trouble code, or disconnect the battery’s ground cable for ten seconds orlonger and then reconnect it.
(8) Adjust the basic idle speed (engine speed adjusting screw). (Refer to
P.13-33.)
(9) Adjust the throttle position sensor.
-rottle position ” ynsor connector
(2) If a scan tool is not used, perform the following operation.
< 1989 models> @ Disconnect the throttle position sensor connector and
use the special tool (test harness) between the discon-
nected connector.
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THROTTLE POSITION SENSOR ADJUSTMEiW&
Caution
The adjustment of the throttle-position sensor should be
made after completion of the basic idle-speed adjustment.
(1) Connect the scan tool to the data link connector (white).
,

FUEL SYSTEM - On-Vehicule Inspection of MFI Components13-41
Ciaarette
COMPONENTS INSPECTION PROCEDURE-
USING THE SCAN TOOL
Ml BYBAG
(1) Switch OFF the ignition switch.
(2) Insert the power-supply terminal of the scan tool into the cigarette lighter socket.
lf it is necessary to make the inspection while cranking the
engine, use the battery harness to take power directly from
the battery.
(3) Connect the scan tool to the data link connector.
(4) Switch ON the ignition switch.
(5) Select the vehicle model and the system. l Select by pressing the
m key.
(6) Select the function, and then check the input and outputsignals of the engine control module.If there is an abnormal condition, check the body harness,
the component itself, etc., and repair as necessary.
l Function selection menu
q SELF-DIAG CODE
q DATA LIST
q ACTUATOR TEST
q SPECIAL TEST
l After checking, press the m key.
(7) After making the repair, use the scan tool to recheck, and confirm that the abnormal condition of the input and output
signals has been corrected to the normal condition by the
(9) FrizE’the diagnostic trouble code from the memory.
lUse the scan tool to make the erasure. (Refer to P.13
17.)
lSwitch OFF the ignition switch and disconnect the ground

cab\e from the batteq Ie’tm
a\ for ten seconds

13-50 FUEL SYSTEM - On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan Tool
Item No. Data display Inspection conditions
12Sensor de-
tection air
volume (fre-
quency) . Engine coolant
temperature: 85-95°C(185-205°F). Lights, cooling fan, elec-
trical accessories: OFF
. Transaxle: neutral (iVT
models: “P” range)
RacingFrequency in-
creases 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].
Regular waveform 03A0203
HARNESS INSPECTION
@
Harness sideconnector
6
0-0
~
0
=
Using Oscilloscope
(1) Run the engine at idle speed.
(2) Connect the probe to the
osilloscope pick-up point a
s
shown in the circuit diagram, and check the wave form.
Measure the power supply voltage.
. Connector: Disconnected
. Ignition switch: ON
--P
IRepair the
Harness sideconnector
Measure the terminal voltage.
. Connector: Disconnected
. Ignition switch: ON ~

0
OK’ 30
Repair the
harness
.
cm-an)
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13-62 FUEL SYSTEM -On-Vehicule Inspection of MFI Components
INSPECTION
Using Scan tool
FunctionItem No.
Data reading 26 Data display
Inspection conditions Switch
status Ignition
switch: ON
(Check after pumping
accelerator several times.) Throttle valve
Normal indication
To idle position
ON
Slightly openedOFF
HARNESS INSPECTION
Harness sideconnector
Y
OlR085
motor connector1 FUO480
Measure the power supply voltage of
the closed throttle position switch.
. Connector: Disconnected
. Ignition switch: ON
IVoltage (V)I
I4 or moreI
Repair theharness.
c@a-m)
SENSOR INSPECTION
(1) Disconnect the idle speed control motor connector.
(2) Check the continuity between terminal
@ and body ground.
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IAccelerator DedalIContinuitvI
DepressedNon-conductive (42)
Released Conductive (0. Q)
(3) If out of specification, replace the idle speed control motor
assembly.

FUEL SYSTEM - On-Vehicule Inspection of MFI Components13-65
(1) Improper adjustment of the basic idling speed.
(2) Deposits adhering to the ttirottle valve.
(3) Air being taken into the intake manifold due to a gasket leak, etc.
OPERATION
ISC motor position sensor is a variable resistor type,
and is integrated in the
ISC motor system. The slid-
ing pin of
ISC motor position sensor is in contact
with the end of the plunger. Therefore, as the plun- ger moves, the internal resistance of
ISC motor pos-
ition sensor varies. This leads to the variation of the (4) Improper seating of the EGR valve seat.
(5) lmcomplete combustion within a cylinder. (Mal-
function of spark plugs, ignition coil, injectors,
compression pressure, etc.)
the plunger position of the
ISC motor system, and
sends the signal to ECM. ECM processes the
ISC
motor position sensor signal, idle signal, coolant
temperature signal, load signal (A/T &
A/C) and ve-
hicle speed signal to control the opening angle of
the throttle valve and revolution speed during
en-
output voltage. ISC motor position sensor detects gine idling.
TROUBLESHOOTING HINTS
Since idling is not controlled when ISC motor posi-
tion sensor is troubled, idling may not be evenly
maintained.
INSPECTION
Using Scan tool
FunctionItem No. Data display Inspection conditions Load conditions
Standard value
Data reading 15 Sensor detec-
. Engine coolant tempera-
Air conditioning 500- 1,300 mV
tion voltage
ture: 85-95’C (185-203°F)
switch: OFF
. Lights, cooling fan, electrical accessories: OFF Air conditioning 800-
1,800 mV. Transaxle: neutral (A/T
mod-
switch: ON
els: “P”
range)
1 Closed throttle position Air conditioning900- 1,900 mVswitch: ON (The compressorswitch: ON
clutch must be operating Select lever:
when the air conditioning shift to “D”
switch is ON.)
range.* Engine: running at idle
NOTEThe idle speed control motor position sensor output voltage may be about\
500 mV higher than indicated above when
the vehicle is new [driven approximately 500 km (300 miles) or less].
CautionBefore shifting the select lever to the “D” range, apply the brake\
s to prevent the vehicle from moving forward.
HARNESS INSPECTION
Measure the power supply voltage of
the idle speed control motor position
ei;;;it;;sco$ected
__...._ -.-
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FUEL SYSTEM -On-Vehicule
Inspection of MFI Components13-91
INSPECTION
Using Scan tool
FunctionItem No. Data display
Data reading 41
III~~~ion
Inspection conditions Engine coolant temperature Standard value
Engine cranking At
0°C (3~2°F)“~Approx. 21 ms
At
20°C (68°F)Approx. 43 ms
At
80°C (176°F)Approx. 10 ms
FunctionItem No.
Data reading 41
L
Data display
Ac&a$ion
Inspection conditions
. Engine coolant tempera- ture:
85-95°C (185-205°F)* Lights, cooling fan, electric-al accessories: OFF
. Transaxle: neutral
(A/T models: “P” range) Engine condition
Standard value
I
750 rpm (Idling)2.5-4.0 ms
I
NOTE*I: The injector activation time indicates the time under the following con\
ditions: a power source voltage of 11V and a
cranking rpm of 250 rpm or less.
**: 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].
FunctionItem No.
Actuator test
01
02
03
04
Description
No.
1 injector is shut off.
No. 2 injector is shut off.
No. 3 injector is shut off.
No. 4 injector is shut off. Inspection conditions
Normal indication
Engine: idling after warm The idling condition
changes more.
r”sput off the injectors in(Either becomes more un-sequence during after stable, or engine stalls.)
engine warm-up, check
the idling condition.)
-
I i-. --.-~-db$- A: Injector~__
Normal waveformdrrve time
HARNESS INSPECTION
1
P
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 of
the injector.
. Connector: Disconnected. Ignition switch: ON
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