engine MITSUBISHI ECLIPSE 1991 Service Manual

14-50FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>THROllLE
POSITION SENSOR ADJUSTME!-T’“.
(1) Slacken the accelerator cable enough.
6FU13%(2) Connect a digital voltmeter between terminal 19 (throttle
position sensor output voltage) of the engine control unit
and terminal 24 (ground).
(3) Set the ignition switch at ON (do not start the engine) and
check that the output voltage from the throttle position
sensor is as specified.
Standard value:
0.48-0.52 V(4) If it is out of specification adjust by loosening the throttle
position sensor mounting screws and rotating the throttle
position sensor. After adjustment, tighten the screws
firmly.
NOTE1. Clockwise rotation of the throttle position sensor
increases the output voltage.
2.For information concerning the removal and installationof the throttle body, refer to
P.14-89.(5) Set the ignition switch at OFF.
(6) Adjust the free play of the accelerator cable.
(7) Remove the voltmeter.
(8) Disconnect the negative battery cable, and reconnect it
more than
10 seconds later. (By doing so, the memory
storing the diagnosis data during the idle speed control
adjustment is cleared.)

FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>14-51THROTTLE BODY (THROTTLE VALVE AREA)
CLEANINGNl4FtU
(1) Warm up the engine, then stop it.
(2) Remove the air intake hose from the throttle body.
(3) Plug the bypass passage inlet of the throttle body.
CautionDo not allow cleaning solvent to enter the bypass
passage.(4) Spray cleaning solvent into the valve through the throttle
body intake port and leave it for about 5 minutes.
(5) Start the engine, race it several times and idle it for about 1minute. If the idling speed becomes unstable (or if the
engine stalls), slightly open the throttle valve to keep the
engine running.
(6) If the throttle valve deposits are not removed, repeat steps
(4) and (5).
(7) Unplug the bypass passage inlet.
(8) Attach the air intake hose.
(9) Disconnect the battery terminal for 10 seconds or more,
and then reconnect it.
(lO)Adjust the basic idle speed. (Refer to P.14-48.)
RELEASE OF RESIDUAL PRESSURE FROM HIGH
PRESSURE FUEL HOSE
N14FGAFRefer to
P.14-44.FUEL PUMP OPERATION CHECK
N14FDAG(1) Set the ignition switch at OFF.
(2) Check that when the battery voltage is directly applied to
the fuel pump check terminal, the operating sound of the
pump can be heard.
NOTESince the high pressure fuel pump is installed in the fuel
tank, its operating sound cannot be readily heard. Remove
the fuel tank cap and listen to the operating sound through
the filler port.
I(3) Hold the high pressure fuel hose between your fingers and
check that the fuel pressure can be felt.

14-52FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>
IDLE POSITION SWITCH ADJUSTMENT
Caution
N14UDAThe idle position switch has been adjusted by the manu-
facturer.Do not, therefore, disturb the setting of the idle-position
switch.
If the setting is disturbed as a result of carelessness, or if
the idle-position switch is replaced, make the necessary
setting as described below.
(1) Sufficiently loosen the tension of the accelerator cable.
(2) Disconnect the connector of the idle position switch (fixed
speed adjusting screw).
(3) Loosen the lock nut of the idle position switch (fixed speed
adjusting screw).
(4) Sufficiently loosen the idle position switch by turning it in
the counterclockwise direction and fully close the throttle
valve.Caution
Be sure to completely close the throttle valve.
(5) Connect a tester (ohm range) between the switch’s
terminal and the body.
(6) Turn down the idle position switch until it enter the “ON”
state where the switch establishes a continuity to body
(this point is called “touch point”). Turn the switch down
15/16 of a turn more from that point.
NOTEThe “touch point” refers to the point where the throttle
valve begins opening.
(7) While holding the idle position switch to make sure that it
does not turn, tighten the lock nut.
(8) Adjust the accelerator cable.
(9) Adjust the basic idle speed. (Refer to P.14-48.)
(lO)Setting the throttle position sensor.
FUEL PRESSURE TESTN14FNAO(1) Reduce the fuel pressure in the fuel line.
(Refer to
P.14-44.)(2) Disconnect the high pressure fuel hose from the delivery
pipe.Caution
Cover the hose connection with shop towel to prevent
splash of fuel that could be caused by residual pressurein the fuel pipe line.
(3) Remove the throttle body stay.

FUEL SYSTEM - Service Adjustment Procedures <2.0L Enaine>14-53
MD998709
MD998742
I
FU01571-(4) Connect a fuel pressure gauge to the special tool (hose
adapter).Use a suitable O-ring or gasket between the fuel-pressure
gauge and the special tool so as to seal in order to preventfuel leakage at this time.
(5) Install the special tool, which was set in place in step
(4),
between the delivery pipe and the high-pressure fuel hose.(6) Connect the
0 terminal of the battery.
(7) Apply battery voltage to the fuel pump check terminal and
activate the fuel pump; then, with fuel pressure thus
applied, check to be sure that there is no fuel leakage fromthe pressure gauge or the special tool connection part.
(8) Start the engine and run at curb idle speed.
(9) Disconnect the vacuum hose from the pressure regulator
and clog the vacuum hose end. Measure the fuel pressure.Standard value:
Turbo>330-350 kPa (47-50 psi) at curb idle

250-270 kPa (36-38 psi) at curb idle

290-320 kPa (41-46 psi) at curb idle
(10)Measure the fuel pressure when the vacuum hose is
connected to the pressure regulator:
Standard value:
Approx. 270
kPa (38 psi) at curb idle
Approx.
190 kPa (27 psi) at curb idle
Approx. 230
kPa (33 psi) at curb idle

14-54FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>
(11)Race the engine repeatedly in two or three series. Then
check that the fuel pressure does not fall when the engine
is running at idle.
(12)Check to be sure that there is fuel pressure in the return
hose also (by gently pressing the fuel return hose with a
finger while repeatedly racing the engine).
NOTEThere will be no fuel pressure in the return hose when the
volume of fuel flow is not sufficient.
(13)lf the results of the measurements made in steps (9) and
(10) above are not within the standard value, use the table
below to determine the probable cause, and then make the
necessary repair.
Condition
Fuel pressure too lowProbable causeRemedy
a. Clogged fuel filtera. Replace fuel filter.
b. Fuel leaking toward return port due tob. Replace fuel pressure regulator.
improper seating of valve in fuel pressure
regulator
c. Low delivery pressure of fuel pumpc. Replace fuel pump.
Fuel pressure too higha. Stuck valve in fuel pressure
a. Replace fuel pressure regulator.regulator
b. Clogged or bent fuel return hose or pipeb. Repair or replace hose or pipe.
Fuel pressure witha. Clogged or broken vacuum hose or nipplea. Repair or replace vacuum hose or
vacuum hose connected
nipple.
not different from fuel
pressure with vacuumb. Stuck valve in fuel pressure regulator or
b. Replace fuel pressure regulator.
hose not connecteddefective valve seating
(14)Stop the engine and check for change in fuel pressure
gauge indication, which should not drop.
If the gauge indication drops, observe the rate of drop and
determine and remove the causes according to the
following table.
Condition
Fuel pressure drops
slowly after engine is
stopped.Probable cause
Leakage from injectorRemedy
Replace injector.
Fuel pressure drops
im-Check valve in fuel pump does not closeReplace fuel pump.
mediately after engine is
stopped.
(15)Reduce the fuel pressure in the fuel line.
(16)Disconnect the high pressure fuel hose and remove the
fuel-pressure gauge from the delivery pipe.
Caution
Cover the hose connection with shop towel to prevent
splash of fuel that could be caused by residual pressurein the fuel pipe line.
(17)Mount a new O-ring in the groove at the end of the high
pressure fuel hose.

FUEL SYSTEM - Service Adjustment Procedures <2.0L Engine>14-55
(18)Connect the high-pressure fuel hose,,to the delivery pipe
and tighten the screws to the specified torque.
(19)Check for fuel leaks.
@I Apply battery voltage to the fuel pump check terminal
to operate the fuel pump.
@ With fuel pressure acting, check the fuel line for leaks.
A
E2li:>
/ )
Engine speed (rpm)lFU4l6EGR VALVE CONTROL VACUUM CHECK
NlQFVBBlCheck Condition
Engine coolant temperature:
85-95°C (185-205°F)
(1) Disconnect the vacuum hose from the throttle body EGR
vacuum nipple and connect a hand vacuum pump to the
nipple.(2) Start the engine and check to see that, after raising the
engine speed by racing the engine, vacuum raises pro-
portionately with the rise in engine speed.
NOTEIf there is a problem with the change in vacuum, it is
possible that the throttle body port may be clogged and
require cleaning.PURGE PORT VACUUM CHECK
Check Condition
N14FVBClEngine coolant temperature:
85-95°C (185-205°F)
(1) Disconnect the vacuum hose from the throttle body purge
hose nipple and connect a hand vacuum pump to the
nipple.
Engine speed (rpm)3FU262(2) Start the engine and check to see that, after raising the
engine speed by racing the engine, vacuum remains fairly
constant.
NOTE
If there is no vacuum created, it is possible that the throttlebody port may be clogged and require cleaning.

IL SYSTEM -MPI Svstem InsDection 4.8L Enaine>14-56FUE- _ ~-~~~~~ ~~ ~,~.
MPI SYSTEM INSPECTION <1.8L Engine>COMPONENTS
LncAT’n”’Ignition timing adjustment terminal
Fuel
ourno check terminal
Nl4PAAMAir-flow sensor
Intake air temperature sensor
Barometric pressuresensorCoolant temperature
sensornhibitor switch (A/T)
Inhibitor switch
-xT==-TL--==- IOlAO422
/Pxygen sensor

FUEL SYSTEM - MPI System Inspection <1.8L Engine>
EGR control solenoid valve
[Calif. only]Purge control solenoid valve
Purge control
-/Y solenoid valve_
ISC servo.Idle Dositionswitch, MPS
Crankshaft angle sensor, TDC sensor
EGR temperature sensor
[Calif. only]
Y-4
16A0802 \
)n ject 0 r 1ture sensor
\I/OlA0407
@Power
steermg fluld pressure switch
ressure switch

14-58FUEL SYSTEM -MPI System Inspection <1.8L Engine>
MALFUNCTION INDICATOR LIGHTNWQAB
Among 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
notmal ‘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.
Items indicated by the lightening malfunction light
Engine control unit
Oxygen sensor
Air-flow sensor
Intake air temperature sensor
Throttle position sensor
Motor position sensor
Engine coolant temperature sensor
Crank angle sensor
No. 1 cylinder TDC sensor
Barometric pressure sensor
Ignition timing adjustment signal
Injector
Fuel pump
EGR system Caution
The malfunction indicator light lights up when the ignition
timing adjustment terminal is short-circuited
,‘t’o ground.
Consequently, it lights up ,when the ignition timing
adjustment is grounded when adjusting ignition timing,
but in this case there is no abnormality.
MALFUNCTION INDICATOR LIGHT INSPECTlON
When turning on the ignition switch, check that the light comes
on.
NOTElf the light does not come on, check the harness and light for
breakage.SELF-DIAGNOSIS
Nl4PMFaThe engine control unit monitors the input/output signals
(some signals at all times and the others under specified
conditions) of the engine control unit.

FUEL SYSTEM - MPI System inspection <1.8L Engine>14-59
--..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.
Caution
If 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.
perature sensor
CautionFor the malfunction code of the ignition timing adjustment
signal, the light for the ignition timing adjustment terminal
lights up when short-circuited to ground.
Consequently, it is output when the ignition timing
adjustment is grounded when adjusting ignition timing,
but in this case there is not abnormality.
CHECK PROCEDURE (SELF-DIAGNOSIS)N14PCAElPrecautions for Operation
(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.