Idle MITSUBISHI GALANT 1989 Service Owner's Guide

13-16
FUEL SYSTEM - Troubleshooting
FAILSAFE/BACK-UP FUNCTIONS LIST
If trouble with any major sensor is detected by the on-board diagnostic,\
the vehicle will be kept in the safe
driving conditions according to the preset control logic.
Trouble item Control content for trouble
Volume air flow Fuel injection timing and ignition timing are determined according to th\
e throttle position
sensor sensor
(TPS) and engine revolution speed signal (crankshaft position sensor signal)\
.
Intake air temperature The control is executed with the suction air temperature regarded as
25°C (77°F).
sensor
Throttle position The fuel injection rate is not increased for acceleration according to t\
he throttle position
sensor
(TPS)sensor signal.
Idle speed control After the idle speed control motor plunger is driven and contracted, the\
idle revolution speed
motor position sensor is not controlled.
Engine coolant The control is executed with the engine coolant temperature regarded as \
8OO.C (176°F).temperature sensor (Even if the sensor signal becomes normal again, the control is continued
until the ignltlon
switch is turned off.)
Camshaft position Simultaneous injection of fuel is executed for all cylinders. (In this \
case, the
No.1 cylinder top
sensor dead center is not detected at all after the ignition key is turned on.)\
Barometric pressure The control is executed with the pressure regarded as 760 mmHg
(30
in.Hg).
sensor
Oxygen sensor Closed loop control of the air/fuel mixture ratio is not executed.
i
READ OUT OF DIAGNOSTIC TROUBLE CODE
Precautions for operation
(1) When battery voltage is low, no detection of failure is possible. Be sure to check the battery for voltage and
other conditions before starting the test.
(2) On-board diagnostic item is erased if the battery or the engine control module connector is discon-
nected. Do not disconnect the battery before the di-
agnostic result is completely read.
Using Scan Tool
(1) Switch OFF the ignition switch.
(2) Connect the power-source terminal of the scan tool to the
cigarette lighter socket.
(3) Connect the scan tool to the data link connector. (4) Turn ignition switch to ON.
(5) Using the scan tool, read out and make a note of the
on-
board diagnostic output.
(6) Refer to the diagnostic chart, and repair the indicated loca-
tion of malfunction.
(7) Erase the diagnostic trouble code. (Refer to
P.13-17.)
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FUEL SYSTEM - Troubleshooting 13-17
\ I\-\\\\\\6FUO807
Using Voltmeter
(1) Connect an analog-type voltmeter between the ground/
terminal and the on-board diagnostic output terminal of the
data link connector.
(2) Set the ignition switch to the “ON” position.
(3) Make a note of the pattern of the on-board diagnostic out- put indicated by the voltmenter’s indicator.
(4) Refer to the diagnostic chart, and repair the indicated loca- tion of malfunction.
(5) Erase the diagnostic trouble code.
On-board
diagnostic
output
terminal
LGround
EbLbtR MEMORY OF DIAGNOSTIC TROUBLE
If the Scan Tool is Used
Connect the scan tool to the data link connector, and then
erase by following the steps below.)
(1) To erase diagnostic trouble code for the engine coolant
temperature sensor or idle speed control motor positionsensor, first turn the ignition switch OFF once and then ON
(2) EE?$t
“4. SPECIAL TEST” of the scan tool’s function-select
menu.
(3) Then select item No.5, “ERASE DIAG.“.
(4) If “ERASE DIAG. CODE?” is displayed, press the “YES” k\
ey.
(5) Input ID code “19”.
(6) When “FINISHED ERASING DIAG. CODE” is displayed,> Ipress the “CLEAR” key.
(7) Read out the on-board diagnostic output and check to be
sure that the correct code is being output.
If the Scan Tool is not Used
(1) Turn the ignition switch to OFF.
(2) Disconnect the ground cable from the battery terminal forten seconds or longer, and then reconnect it.
(3) Read out the on-board diagnostic output and check to be
sure that the correct code is being output.
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FUEL SYSTEM VALVE> - TroubleShooting13-19
PROBLEM SYMPTOMS TABLE (FOR YOURINFORMATION)
:tShock
Surge
Knocking
0,GRun ona (“dieselrng”)
6
Items Symptom
-- -... __----. -~-
The starter IS used to crank the engine, but there IS no
combustron
wrthrn
the cylinders.
(no rnrtral combustron)
and the engine won’t start~-.-__Startrng
problem There IS combustron
wrthrn
the cylrnders.
but then the engrne
soon stalls.
(Initial combustion, then stall)
(Startrng takes a long t1me.l
I
Idling
rnstabrlrty
/ Engrne won’t start qurckly~--_~ -...
Engine speed doesn’t remain constant; changes during idling.
Usually, aludgement can be based upon the movement of the tachometer pointer, and
the
vibration transmitted to the steering wheel, shift lever, body, etc. This is call\
ed rougt
Idling.
The
engtnedoesn’t idle at the usual correct speed.
Thus non-contrnuity of rdlrng Includes the followrng elements(1) Die out
. . . . ..The
engine stalls when the foot IS taken from the accelator pedal,
regardless of whether the vehicle IS moving or not.(2)Pass out . . . ..The
engine stalls when the accelerator pedal IS depressed or while it IS berng
used.
“Hestatton” IS the delay In response of
the vehicle (engine rpm) that occurs
when the accelerator is depressed
Inorder to accelerate from the speed atwhich the vehicle is now traveling, or a
temporary drop in vehicle speed (enginerpm) during such acceleration. Hesltatron
Serious
hesstatlon IS called “sag”.
Poor
acceleration
E Stumbl
e
2
5
Time lFUO223
Poor
acceleration IS rnabilrty
to obtain an acceleration corresponding to the degree of
throttle opening, even though acceleration IS smooth, or the rnabrlrty to reach maxmum
speed.
Engrne rpm response IS delayed when .
the accelerator pedal is initrally
depressed
for acceleratron
from the stopped
condition ldllng
Stumble
Trme lFUO224
The
feeling of a comparatlvley large Impact or vrbration
when the engine IS accelerated
or decelerated.
This IS repeated surging
ahead dunng constant speed travel or dunng
vanable
speed
travel.
A sharp sound
IIke a hammer strtklng the cylinder walls during
dnvtng
and whrch
adversely affects driving.
The
condrtion In which the engrne
continues to run after the lgnltion switch 1s turned to
OFF. Also called
“dreselrng”.
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13-22
FUEL SYSTEM - Troubleshooting
CIRCUIT DIAGRAM (CONTINUED)
< 1989 models>
IGNITIONSWITCHlIGl)#OF?OWERMFIRELAYIGNIlTRANf
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IDLE SPEEDCONTROL MOTORPOSITJON SENSOR
A-53 12El(VEHICLES FOR94CALIFORNIA)
B-02 B @
KX35-AC-HO525A-NY
B-04 m
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FUEL SYSTEM (SOHC-8 VALVE> - Troubleshooting13-27
INJECTOR&INJECTOR&INJECTOR&NJEC
--
!-B-20 -7
!OXYGE!!ENSOR I'(VEHICLES FORCALIFORNIA)
5v
-w-Qz-I-
-
^
_____---______-_- ---____--&vs-- -__---- T18
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>
,..
-----.2
15
12
I
----.58
8
I
1
IDLE SPEEDDATA LINKCONTROL MOTORCONNECTOR
59
cl-11
I
2
1
m
II
!II II1
ib -
I
' OXYGEN SENSOR'(VEHICLES FOR
FEDE89":;
i 63 i
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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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13-34 FUEL SYSTEM -Service Adjustment Procedures
(5) Switch ON the ignition switch (but do not start the engine)and leave as if for 15 seconds or longer.
NOTE
When the ignition switch is switched ON, the idle speed
control plunger extends to the fast-idle opening degree,
and, after 15 seconds have passed, contracts to the initialposition and stops there.
Initial position: the suitable idling position at which the idle speed control motor position sensor output
voltage is
0.9V.
fi Idle-speed
--\\screw 6FU1404(6) Switch OFF the ignition switch.
(7) Disconnect the connector of the idle-speed control motor, and then secure the
ISC motor at the initial position.
(8) Sufficiently loosen the fixed SAS.
(9) Start the engine and let it idle.
(10)Check the basic idling speed.
If the scan tool is used, select
No.22 and then read the id-
ling speed.
Basic idling speed: 750
+-50 rpm
NOTE
The engine speed may be 20 to 100 rpm lower than
indicated above for a new vehicle [driven approximately
500 km (300 miles) or less], but no adjustment is necessary.If the engine stalls or the rpm is low even though the
vehicle has been driven approximately 500 km (300 miles) or more, it is probable that deposits are adhered to the
throttle valve, so clean it. (Refer to
P.13-35.)
(1l)lf there is a deviation from the standard value, turn the en-
gine speed adjustment screw to make the adjustment.
NOT
E
When the engine speed adjustment screw is turned to make the adjustment, use a hexagonal wrench if possible,
and, in order to prevent backlash of the screw, make the
final adjustment at the tightening side.
(12)Tighten the fixed SAS until the engine speed increases;
then return the fixed SAS to find the point (the “touch
point”) at which the engine speed does not decrease.
Then, from that point, return the fixed SAS and additional
one-half turn. (13)Switch
OFF the ignition switch.
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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).
,

13-36 FUEL SYSTEM - Service Adjustment Procedures
:I989 models>
M
D9684783FUO179
models> Sensor side connector
@ Connect a digital type voltmeter between terminal @
(blue clip, sensor output) of the throttle position sensor
and terminal
@I (red clip, sensor ground).

@I Disconnect the throttle position sensor connector and use the special tool (test harness set) between the
disconnected connector.
@ Connect a digital type voltmeter between terminal @
(sensor output) of the throttle position sensor and
terminal
@I (sensor ground).
1 FU0619
(3) Switch ON the ignition switch (but do not start the engine) and leave as is for 15 seconds or longer.
NOTE
When the ignition switch is switched ON, the idle speedcontrol plunger extends to the fast-idle opening degree,
and, after 15 seconds have passed, contracts to the initial
position and stops there.Initial position: the suitable idling position at which the idle speed control motor position sensor output
voltage is 0.9 V.
(4) Check the throttle-position sensor’s output voltage. If the scan tool is used, select No. 14 and then read the
throttle-position sensor’s output voltage.
Standard value: 0.48-0.52
V
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