1991 MITSUBISHI ECLIPSE check engine

FUEL SYSTEM - MPI Svstem Inspection <1.8L Engine>18-63
Throttle position sensor
Groundoutput
Sensorpower
SUPPlY(5V)
1 FUO507
6FU1244Motor
Dosition sensor connector
(motor ‘side, front view)
T
6FU1247Motor position sensor
connector(motor side, front view)
6FU1252
THROITLE POSITION SENSOR
INSPECTION
Nl4OBBKa(1) Disconnect the throttle position sensor connector.
(2) Measure resistance between terminal
@I (sensor ground)
and terminal
@ (sensor power).
Standard value: 3.5-6.5
kGI(3) Connect a pointer type ohmmeter between terminal
@(sensor ground) and terminal
@ (sensor output).
(4) Operate the throttle valve slowly from the idle position to
the full open position and check that the resistance changessmoothly in proportion with the throttle valve opening
angle.(5) If the resistance is out of specification, or fails to change
smoothly, replace the throttle position sensor.
Throttle position sensor installation torque:
1.5
- 2.5 Nm (1.1 - 1.6 ftlbs.)
IDLE POSITION SWITCH
INSPECTION
N14QKADa(1) Disconnect the connectors of the motor position sensor.
(2) Check the continuity between terminal
@ and the body
ground.
IAccelerator pedalIContinuityI
DepressedINon-conductive (@J fl)I
ReleasedIConductive (0 fl)I(3) If defective, replace the idle speed control servo assembly.
MOTOR POSITION SENSOR
INSPECTION
N140lAJ(1) Disconnect the motor position sensor connector.
(2) Measure the resistance between terminals
@ and 0.Standard value: 4
- 6 kfi

14-64FUEL SYSTEM -MPI System Inspection <1.8L Engine>
Idle speed controlservo connector
6FU098t(3) Disconnect the idle speed control servo connector.
(4) Connect DC
6V between terminals @) and @ of the idle
speed control servo connector, and then measure the
resistance between terminals
@ and @ of the motor
position sensor connector when the idle speed control
servo is activated (caused to expand and contract).
Standard value: Smooth increase/decrease in accord-
ance with extension and retraction of
idle speed control servo plunger.
Caution
Apply only a 6V DC or lower voltage. Application of
higher voltage could cause locking of the servo gears.
(5) If there is a deviation from the standard value, or if the
change is not smooth, replace the idle speed control servo
assembly.
OXYGEN SENSORN14QDBAb
INSPECTIONCaution
1. Before checking, warm up the engine until engine
coolant temperature reaches 85 to
95°C (185 to 205°F).2. Use an accurate digital voltmeter.
(1) Disconnect the oxygen sensor connector and connect a
voltmeter to the oxygen sensor connector.
(2) While repeating engine racing, measure the oxygen sensor
output voltage.
EngineOxygen sensor
output voltageRemarks
Race0.6- 1 .OVMake air-fuel mixture
rich by accelerator
operation
NOTEFor removal and installation of the oxygen sensor, refer
toGROUP 11
- Exhaust Manifold.
Oxygen sensor installation torque:
40
-50 Nm (30 - 36 klbs.)
EGR TEMPERATURE SENSOR NIIRCHA~Refer to GROUP 25
- Exhaust Gas Recirculation System.
VEHICLE SPEED SENSORN14QEEBaRefer to GROUP 8
- Meters and Gauges.
AIR CONDITIONER SWITCHRefer to GROUP 8
- Column Switch.
N14QQABa

FUEL SYSTEM - MPI Svstem InsDection <1.8L Engine>14-65
3FUO349
/--
’ 3FU03991
Idle speed controlservo connector(motor side, front view)
3FUO393
INHIBITOR SWITCHN14QRACsRefer to GROUP 21
- Service Adjustment Procedures.
POWER STEERING OIL PRESSURE SWITCH
N14flCJBRefer to GROUP 19 for power steering system inspection.
INJECTORSN14QTAGCHECKING 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.
NOTEIf 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
unit is suspected.
MEASURING RESISTANCE BETWEEN TERMINALS
(1) Remove the injector connector.
(2) Measure the resistance between the terminals.
Standard value: 13
- 16 L(Z [at 20°C (68”F)I(3) Install the injector connector.
IDLE SPEED CONTROL SERVO
INSPECTION
NlQQUAAb(1) Disconnect the idle speed control servo connector.
(2) Check continuity of the idle speed control servo coil.
IMeasuring terminalsIContinuityI
@ - @ Conductive5 to 35 fi resistance
at 20°C (68°F)

14-66FUEL SYSTEM -MPI System Inspection 4.8L Engine>
6FU1253
-1 Batterv
I6FUO751
03AOO50
03AOO57(3) Connect
6V DC between terminal @ and terminal @ of the
idle speed control servo connector, and check to be sure
that the idle speed control servo operates.
CautionApply only a 6V DC or lower voltage. Application of
higher voltage could cause locking of the servo gears.
(4)
If not, replace idle speed control servo as an assembly.
CONTROL RELAY
INSPECTION
NWWAE(1) Remove the control relay.
(2) Inspect the continuity between the control relay terminals.
Inspection terminalsContinuity
l---$+-l Yes (approx. 9552)
B-0
@-@
~~~
Yes (approx. 35Q)
Yes in 1 direction only(3) Use jumper wires and connect control relay terminal
@ to
the battery
@ terminal and terminal @ to the battery @
terminal.Caution
Be very careful when connecting the jumper wires
because the relay will be damaged if a mistake is made
with the contact terminals.
(4) With the battery
0 terminal jumper wire connected and
disconnected, check the continuity between control relay
terminals @-@I.
Continuity between terminals 0-B(5) Use jumper wires to connect control relay terminal
@I to
the battery
@ terminal and terminal @ to the battery 0
terminal.(6) With the battery
0 terminal jumper wire connected and
disconnected, check the continuity between control relay
terminals @-@I.
Continuity between terminals 0-a
1(7) Replace the control relay if faulty.

14-68FUEL SYSTEM - MPI System Inspection <2.0L DOHC Engine>
MPI SYSTEM INSPECTION <2.0L DOHCCOMPONENTS LOCATION

Throttle
Dosition sensor
Crankshaft angle sensor
‘DC sensor
N14PAANIgnition timing adjustment terminal
Fuelpumpcheck terminal
I /B \ Q-terminalFuelpump check\Ignition timing adjustment terminal
Fuelpumpcheck terminal
ustment terminalir-flow sensor
takeair temperature sensor
arometric pressure sensornhibitor switch (A/T only)
OlA040i

14-70FUEL SYSTEM - MPI System Inspection <2.0L DOHC Engine>

Throttle position sensor
tm\ m24-T.\/ \Waste aate control valve [Turbo
only1
IO;A0455I nition timing adjustment terminal
9uel pump check terminal
----Fuel
pump checkAir-flow sensor
Intake air temperature sensor
BarometricDressure sensor
1 (built in intakeair’ Y/I
I
iemperature sensor andbarometricpressure sensor) Lsensor

14-72FUEL SYSTEM - MPI Svstem InsDection <2.0L DOHC Engine>
MALFUNCTION INDICATOR LIGHTAmong the self-diagnosis items, a malfunction indicator light
comes on to notify the driver of the emission control items
when an irregularity is detected.
However, when an irregular signal returns to normal and the
engine control unit judges that it has returned to normal. the
malfunction indicator light goes out.
Moreover, when the ignition switch is turned off, the light goes
out. Even if the ignition switch is turned on again, the light doesnot come on until the irregularity is detected.
Here, immediately after the ignition switch is turn on, the
malfunction indicator light is lit for 5 seconds to indicate that
the malfunction indicator light operates normally.
I--l
klfunctionindicator light
Items indicated by the lightening malfunction light
Engine control unit
Oxygen sensor
Air flow sensor
Intake air temperature sensor
Throttle positron sensor
Engrne coolant temperature sensor
Crank angle sensor
Top dead center sensor
Barometric pressure sensor
Detonatron sensor
Injector
Fuel pump
EGR
Ignition co11
/
iMALFUNCTION INDICATOR LIGHT INSPECTION
When turning on the ignition switch, check that the light comes
on.
NOTEIf the light does not come on, check the harness and light for
breakage.

FUEL SYSTEM - MPI System Inspection <2.0L DOHC Engine>
SELF-DIAGNOSIS14-73
N14PAAEThe engine control unit monitors the input/output signals
(some signals at all times and the others under specified
conditions) of the engine control unit.
When it is noticed that an irregularity has continued for a
specified time or longer from when the irregular signal is
initially monitored. Passing a certain number, the engine
control unit judges that an irregularity has occurred, memorizesthe malfunction code, and outputs the signal to the
self-diagnosis output terminal.
There are 14 diagnosis items, and the diagnosis results can beread out with a voltmeter.
Moreover, since memorization of the malfunction codes is
backed up directly by the battery, the diagnosis results are
memorized even if the ignition key is turned off. The malfunc-
tion codes will, however, be erased when the battery terminal
or the engine control unit connector is disconnected.
CautionIf the sensor connector is disconnected with the ignition
switch turned on, the malfunction code is memorized. In
this case, disconnect the battery terminal
(-) for 10seconds or more, and the diagnosis memory will be
erased.The 14 diagnosis items are provided as follows, and if plural
items are activated, they are all indicated sequentially from thesmallest code number.
arometnc pressure sensor
CHECK PROCEDURE (SELF-DIAGNOSIS)Precautions for OperationN14PCAE2(1) When battery voltage is low, no detection of failure is
possible. Be sure to check the battery for voltage and otherconditions before starting the test.
(2) Diagnosis item is erased if the battery or the engine controlunit connector is disconnected. Do not disconnect the
battery before the diagnosis result is completely read.
(3) After check and correction are over, disconnect ground
cable for 10 seconds or more from negative terminal of
battery and connect it again to make sure that failure code
is erased.