MITSUBISHI SPYDER 1990 Service Repair Manual

Wave pattern observation points
Point:Condition of wave pattern build-up section and maximum voltage (Refer to abnormal wavepattern
examples 1 and 2.)
Condition of wave pattern build-up section and maxi mum voltageProbable cause
Rises from approx. to approx. at the top-rightNormal
rectangular wave Open-circuit in ignition primary circuit
Rectangular wave at power voltage Ignition power transistor malfunction
--- Normal wave pattern
-- Normal wave pattern
Examples of abnormal wave
l
Example 1
Wave pattern during engine cranking
of problem
Open-circuit in ignition primary circuit
Wave pattern , ,
Top-right part of the build-up section cannot
voltage value is approxiinatety too
l Example 2
Wave pattern during engine cranking
Cause of problem
Malfunction in ignition power transistor
Wave pattern characteristics
Power voltage results when the ignition power trans istor
is ON.
Revision

THROTTLE BODY
CLEANING
1.
2.
Start the engine and warm it up the coolant is
to higher and then stop the
Remove the air intake hose from the
.
3.
4.
5.
6.
7.
8.
9.
Plug the bypass passage inlet of
Caution
Do not allow cleaning solvent to enter the bypass
passage.
Spray cleaning solvent into the valve through throttle’
body intake port and leave it for about 5
Start the engine, race it several times and idle it for about
1 minute. If the idling speed becomes unstable (or if the
engine stalls) due to the bypass passage being plug ged,,
slightly open the throttle valve to keep the
If the throttle valve deposits are removed, repeat
steps 4 and 5.
U n p l u g t h e p a s s a g e i n l e t .
Attach the air intake hose.
Use the scan tool to erase the
code.
10. Adjust the basic idle speed. (Refer to
N O T E If the engine hunts while idling after
of the
basic idle speed, disconnect the cable from the battery
for 10 seconds or more, and then reconnect it and r un
the engine at idle for about
minutes.

Throttle
CLOSED THROTTLE SWITCH
THROTTLE POSITION SENSOR ADJUSTMENT
NOTE
When using the scan tool, service item 26
and observe the ON/OFF changes posi-
tion switch instead of performing
If the scan
tool is not available, follow the steps bellow.
1.Disconnect the connector the throttle position sensor.
2.Connect an ohmmeter between terminal 3 (closed
position switch) and 4 (sensor ground) by using jum per
wires.
177
3.Insert a feeler gauge with a thickness of 0.45 mm
in.) between the fixed SAS and the throttle lever.
4. Loosen the throttle position sensor mounting bol t; then
turn the throttle position sensor body fully counter clock-
wise.
5.In this condition, check for continuity between terminals
3 and 4.
6. Slowly turn the throttle position sensor clockwi se until
the point at which continuity between terminals 3 a nd
4 changes to non-continuity is found.
Tighten the throttle position sensor installation b olt at
that position.
7. Connect the connector of the throttle position s ensor.
8.Connect the scan tool to the data link connector

Terminal 2Terminal 4
--
9. When not using the scan tool, proceed as follows :
(1) Disconnect the throttle position connectors
and connect the special tool.
set, be-
tween the disconnected connectors.
(2) Connect a digital voltmeter
throttle
tion sensor terminal 2 (sensor output) and
4 (sensor ground.)
10. Turn the ignition switch ON (but do not start th e engine).:
11. Check the throttle position sensor voltage.
value:
__
12. If there is a deviation from the’ standard value, check
the throttle position sensor and the
13. Remove the feeler gauge.
14. Switch OFF the ignition switch.
.
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. .

FIXED SAS ADJUSTMENT
NOTE
1. The fixed SAS should not be moved unnecessarily;it has been precisely adjusted by the manufacturer.
2 .
If the adjustment is disturbed for any reason, read just
as follows.
1. Loosen the tension of the accelerator cable suff iciently.
2. Back out the fixed SAS lock nut.
3.Turn the fixed SAS counterclockwise until it is suf ficiently
backed out, and fully close the throttle valve.
4. Turn the fixed SAS clockwise until the throttle lever is
touched (i.e., the point at which the throttle valve begins
to open).
From that point, turn the fixed SAS clockwise anoth er
t u r n .
5.While holding the fixed SAS so that it doesn’t move , tighten
the lock nut securely.
6. Adjust the tension of the accelerator cable.
7. Adjust the basic idle speed.
8.Adjust the closed throttle position switch and the throttle
position sensor. (Refer to

SPEED
NOTE
1.The standard idle speed by,
engine speed the
and there should usually for readjustment.
2. The adjustment, after first:
confirming that the spark plugs; the
air control servo, the compression pressure,
all normal.
1.. The vehicle should be prepared as follows before the
i n s p e c t i o n a n d a d j u s t m e n t .
lEngine coolant temperature:
l Lights, cooling fan and accessories: OFF
‘2.
l Transaxle: Neutral (A/T for range)
Connect the scan tool to the data link connector
N O T E
When the scan tool is connected, the diagnostic tes t mode
control terminal should be grounded.
3. Start the engine and run at idle.
4. Select the item No. 30 of the SCAN TOOL (MUT-II)
Actuator test.
NOTE
This holds the motor at the basic step to adjust the
basic idle speed.
5. Check the idle speed. Standard value: 750
50
NOTE
1. The engine speed may be 20 to 100 lower
than indicated above for a new vehicle [driven appr oxi-
mately 500 km (300 mile) or less], but no adjustment
is necessary.
2.If the engine stalls or the is low even though
the vehicle has been driven approximately 500 km (300 mile) or more, it is probable that deposits ar e
adhered to the throttle valve, so clean it. (Refer to

If not within the standard value range, turn the engine
speed adjusting screw to make the necessary adjustm ent.
NOTE
If the idling speed is higher standard value
even when the engine speed adjusting screw’ fully
closed, check whether or not there is any indicatio n that
the fixed SAS has been moved. If there
indication
that it ‘has been moved,
the fixed SAS. If there;
are no indications that it has been moved, it
possible
that there is leakage as a result
of the
fast idle air valve (FIAV), and, if so, the throttl e body
should be replaced.
7.Press the scan tool clear key, and release the motor
from the Actuator test‘ mode.
NOTE
Unless the motor is the Actuator test mode.
will continue 27 minutes.
8. Switch the ignition switch.
9. Disconnect the scan tool. 10. Start the engine again and let it run at idle s peed for
about 10 minutes; check to be the condition
is normal.
,
. .

Fuel pressure
O-ring or gasket
.
FUEL PRESSURE TEST
1. Release residual the fuel line.
(Refer to
2.Disconnect the high-pressure,, fuel. hose -at the fuel rail’
side.
Caution
Cover the hose with a shop to let
fuel gush out.
3. Remove the union joint and bolt from the special tool
(adapter hose and instead attach the special
tool (hose adapter to the adapter hose.
4. Install a fuel pressure gauge on the adapter hos e that
was set up in step 3.
Use a suitable O-ring or gasket between the fuel pr essure
gauge and the special tool so as to seal in order t o prevent
fuel leakage at this time.
5. Install the special tool, which was assembled in steps
3 and 4 between the fuel rail and the high pressure hose.
6. Connect the fuel pump drive terminal to the batt ery
terminal using a jumper wire to drive the fuel pump. Check
the fuel pressure gauge and special tool connection s
for leaks.
7.Disconnect the jumper wire from the fuel pump drive termi-
nal to stop the fuel pump.
8.
the engine and run at idle.
9. Measure fuel pressure while the engine is runnin g at
idle.
Standard value:
Approx. 230
(33 psi) at curb idle
Engine (Turbo)>
Approx. 270 (38 psi) at curb idle Engine>

AND On-vehicle
10. Disconnect and plug the vacuum hose from the fuel
sure regulator and measure fuel pressure with the hose
end closed by a finger.
Standard value:
( 4 2 - 4 5 a t c u r b ,
(Turbo)> .
idle
11. Check to see that fuel pressure at idle drop
even after the engine has been raced
12. Racing the engine repeatedly, hold the,, fuel r eturn hose
lightly with fingers to that fuel pressure
i n t h e r e t u r n h o s e .
NOTE
If the fuel flow rate is low, there will be no fuel pressure
in the return hose.
13.
any of fuel pressure measured in steps 9 to 12 is out
of specification, troubleshoot and repair according to the
table below.
Symptom Probable cause Remedy
l Fuel pressure too lowClogged fuel filterReplace fuel filterlFuel pressure drops after racinglNo fuel pressure in fuel returnFuel leaking to return side due toReplace fuel pressure regulator
hose poor fuel regulator valve seating or
settled spiing
Low fuel pump delivery pressure Replace fuel pump
Fuel pressure too high Binding valve in fuel pressure
Replace fuel pressure regulator
lator
Same fuel pressure when vacuum
hose is connected and when
connected Clogged fuel return hose or pipe
Clean or replace hose or pipe
Damaged vacuum hose or clogged Replace vacuum hose or clean
nipple
Malfunction of the fuel pressureChecking the fuel pressure control
control system system

14. Stop the engine and
Normal if the reading does
it observe
repair according to “the table,
SymptomProbable
Fuel pressure drops gradually afterLeaky injector
engine is stopped inject&. . ,
Leaky fuel regulator valve seat
Fuel pressure drops Check is held. .mediately after engine is stopped open
15. Release residual pressure from the fuel pipe li ne.
(Refer
16. Remove the fuel pressure gauge and special tool from
the fuel rail.
Caution
Cover the hose connection with a shop towel to pre-
vent splash of fuel that could be caused by some residual pressure in the fuel pipe line.
17. Replace the O-ring at the end of the fuel high pressure
hose with a new one.
16. Fit the fuel high pressure the fuel rail and tighten
the bolts specified torque.
T i g h t e n i n g
‘Apply
drive drive the fuel pump.
(2) Check
fuel for leaks, repair as needed.
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,
.
.