fuel MITSUBISHI LANCER EVOLUTION IV 1998 Owner's Manual

MPI – Troubleshooting13-29

The injector power supply voltage waveform shows a voltage drop caused by resistance of the resistor.
As the amount of current increases, voltage gradually decreases and a spike occurs at the plunger fully
opened position due to counter emf.

Point A: Voltage drop during fuel injection time (Refer to abnormal waveform example 1.)
Difference from standard waveformPossible cause
Voltage drop during fuel injection time is small (there
should normally be a voltage drop of about 10 V).Resistance of resistor is too small. Resistance of injector
is too large.
Point B: Spike when plunger is fully open (Refer to abnormal waveform example 2.)
Difference from standard waveformPossible cause
No spike when plunger is fully openPlunger inoperative

Example 1
[Cause of problem]
Resistance of the resistor is too small.
[Waveform characteristics]
Small voltage drop
Example 2
[Cause of problem]
Plunger is inoperative.
[Waveform characteristics]
No spike when plunger is fully open.
7-4 IGNITION COIL
Perform the same steps as with the conventional 4G9 engine
for the inspection.
Abnormal waveform
Normal waveform

MPI – On-vehicle Service13-30
ON-VEHICLE SERVICE
1. IDLE POSITION SWITCH AND THROTTLE
POSITION SENSOR (TPS) ADJUSTMENT
The thickness of the feeler gauge inserted between the fixed
SAS and throttle lever should be 0.45 mm.
2. FIXED SAS ADJUSTMENT

Turn down one turn after the fixed SAS has touched the
throttle lever.

Turn down 1-1/4 turns after the fixed SAS has touched the
throttle lever.
3. BASIC IDLE SPEED ADJUSTMENT
The basic idle speed should be 850 ± 50 rpm.
4. FUEL PRESSURE MEASUREMENT
The fuel pressure gauge should be installed at the location
shown on the left.

MPI – On-vehicle Service13-31
5. MPI SYSTEM COMPONENTS LAYOUT
NameSymbolNameSymbol
A/C switchQExhaust temperature warning lampS
A/C relayHFuel pressure control valveA
Air flow sensor (with a built-in intake air temperaturesensor and barometric pressure sensor)FIgnition coil and power transistor unitLsensor and barometric pressure sensor)InjectorB
Camshaft position sensorMISC servoD
Control relay and fuel pump relayPOxygen sensorK
Coolant temperature sensorEPower steering fluid pressure switchI
Crank angle sensorJSecondary air control solenoid valveN
Detonation sensorCThrottle position sensor (with a built-in idle switch)D
Diagnosis connectorR
Engine ECUOVehicle speed sensorT
Engine warning lampSWastegate solenoid valveG

MPI – On-vehicle Service13-33
(2) Check that there is continuity (11 to 18 Ω at 20C) across
terminal no. 1 (special tool red clip) and terminal no. 3
(special tool blue clip) of the oxygen sensor connector.
(3) If there is no continuity, replace the oxygen sensor.
(4) Run the engine until the engine coolant temperature
exceeds 80C.
(5) Using jumper wires, connect oxygen sensor terminal no.
1 (special tool red clip) and terminal no. 3 (special tool
blue clip) to battery (+) and (–) terminal, respectively.
Caution
Make sure of the correct connections: if a wrong
connection is made, a broken oxygen sensor results.
(6) Connect a digital voltmeter between terminal no. 2 (special
tool black clip) and terminal no. 4 (special tool white clip).
(7) Race the engine repeatedly to measure the oxygen sensor
output voltage.
Standard value:
EngineOxygen sensor
output voltageNOTE
When
engine is
raced0.6 – 1.0 VWhen engine racing is
repeated to enrich air-fuel
ratio, an operational oxygen
sensor should output a volt-
age of 0.6 to 1.0 V.
NOTE
Use the same procedures to remove and install the oxygen
sensor.
Red clip
Blue clip
MD998464
Red clip
Blue clip
MD998464 Black clip
White clip

MPI – On-vehicle Service13-34
9. INJECTOR CHECK
Injection Condition Check
(1) Release the residual pressure from the fuel pipe line to
prevent fuel from flowing out.
(2) Remove the injector.
(3) Set up the special tools (Injector Test Set, Adapter, Fuel
Pressure Regulator, and Clip) as illustrated below.
(4) From here on, use the same procedure as with the
conventional 4G9 engine for the check.
MD998741
MD998706 MB991607Main hose
BatteryInjectorClip: MD998746Return hose
Fuel Pressure Regulator: MD116395
10. RESISTOR CHECK
(1) Disconnect the resistor connector.
(2) Measure resistance across terminals as detailed below.
Standard value
Measurement terminalsResistance (Ω)
1 – 3
4 – 3
5 5 to 6 5 (at 20C)
5 – 3
5.5 to 6.5 (at 20C)
6 – 3
Resistor

MPI – On-vehicle Service13-35
11. FUEL PUMP RELAY NO.2 CHECK
(1) Remove fuel pump relay No.2.
(2) Using jumper wires, connect fuel pump relay No.2 terminal
(3) to battery (+) terminal, and terminal (1) to battery
(–) terminal, respectively.
(3) Connecting and disconnecting the jumper wire on the
battery (–) terminal end, check for continuity across
terminal (2) and terminal (5), and across terminal (4) and
terminal (5), of fuel pump relay No.2.
Jumper wireContinuity across
terminals (2) and (5)Continuity across
terminals (4) and (5)
ConnectedNoYe s
DisconnectedYe sNo
(4) If the continuity is checked abnormally, replace fuel pump
relay No.2.
12. FUEL PUMP RESISTOR CHECK
(1) Disconnect the fuel pump resistor connector.
(2) Measure resistance across the terminals.
Standard value: 0.6 – 0.9 Ω
(3) If the measurement falls outside the specified range,
replace the fuel pump resistor.
Fuel pump relay No.2
Fuel pump resistor

MPI – Injector13-36
INJECTOR
REMOVAL AND INSTALLATION
Pre-removal Operation
(1) Fuel Discharge Prevention
(2) Air Hose D Removal
(Refer to GROUP15 – Intercooler.)Post-installation Operation
(1) Air Hose D Installation
(Refer to GROUP15 – Intercooler.)
(2) Fuel Leakage Check
O-ring
9 {0.9}83, 6
11
12
O-ring 10 – 13 {1.0 – 1.3}
Engine oil
1
2 3
4
5
6 78 9
10 11 12
Unit: Nm {kgf
m}
4
Removal steps
1. Injector connector
2. PCV hose connection
A3. High-pressure fuel hose connection
4. Fuel return hose connection
5. Vacuum hose connector
A6. Fuel pressure regulator7. Fuel return pipe
A8. Delivery pipe
9. Insulator
10. Insulator
AA11. Injector
12. Grommet

INTAKE AND EXHAUST – Intake Manifold15-9
INTAKE MANIFOLD
REMOVAL AND INSTALLATION
Pre-removal Operation
(1) Fuel Discharge Prevention
(2) Throttle Body Removal (Refer to GROUP 13.)
(3) Front Exhaust Pipe Removal (Refer to P.15-14.)
(4) Air Control Valve Bracket Removal (Refer to P.15-8.)
(5) Strut Tower Bar RemovalPost-installation Operation
(1) Strut Tower Bar Installation
(2) Air Control Valve Bracket Installation
(Refer to P.15-8.)
(3) Front Exhaust Pipe Installation (Refer to P.15-14.)
(4) Throttle Body Installation (Refer to GROUP 13.)
O-ring
Unit: Nm {kgf
m}
15
Engine oil
3 {0.3} 10 – 13 {1.0 – 1.3}
10 – 12
{1.0 – 1.2}
12 – 15 {1.2 – 1.5}
35 {3.6}
9 {0.9}30 {3.1}35 {3.6}20 {2.0}22 {2.2}20 {2.0}
14 14
167
5
17
1521
3
4 6
7 7
19
20
18 8
9 12
1011
13
Removal steps
1. Center cover
2. Ignition coil connector connection
3. Oxygen sensor connector connec-
tion
4. Crank angle sensor connector con-
nection
5. Injector connector connection
6. PCV hose
7. Vacuum hose connection
8. Brake booster vacuum hose con-
nection
9. Vacuum tank, solenoid valve, and
vacuum hose assembly10. Intake manifold stay
11. Oil level gauge guide assembly
12. Vacuum hose and pipe mounting
bolt
13. Fuel return hose connection
A14. Fuel high pressure hose connection
A15. Delivery pipe, injector, and pres-
sure regulator assembly
16. Insulator
17. Insulator
18. Alternator brace stay
19. Intake manifold
20. Intake manifold gasket

INTAKE AND EXHAUST – Intake Manifold15-10
REMOVAL SERVICE POINT
ADELIVERY PIPE, INJECTOR AND PRESSURE
REGULATOR REMOVAL
Remove the delivery pipe with the injectors and pressure
regulator attached to it.
Caution
Care must be taken, when removing the delivery pipe,
not to drop the injector.
INSTALLATION SERVICE POINT
AHIGH-PRESSURE FUEL HOSE INSTALLATION
(1) When connecting the high-pressure fuel hose to the
delivery pipe, apply a small amount of new engine oil
to the O-ring and then insert the high-pressure fuel hose,
being careful not to damage the O-ring.
Caution
Be careful not to let any engine oil get into the delivery
pipe.
(2) Check to be sure that the high pressure hose turns
smoothly.
If it does not turn smoothly, the O-ring may be trapped.
Remove the high-pressure fuel hose to check for damaged
O-ring and then re-insert it into the delivery pipe and
check once again.
(3) Tighten the mounting bolts to the specification.
INSPECTION
INTAKE MANIFOLD CHECK
(1) Check the intake manifold for damage or cracking and
replace it if defective.
(2) Using a straight edge and feeler gauge, check for distortion
of the cylinder head installation surface.
Standard value: 0.15 mm or less
Limit: 0.2 mm
High-pressure
fuel hoseDelivery pipe
O-ring

ENGINE EMISSION CONTROL –
Engine Control System /
Emission Control System 17-2
ENGINE CONTROL SYSTEM
SERVICE SPECIFICATIONS
ItemsStandard value
Idle speed rpm850 ± 50
EMISSION CONTROL SYSTEM
ON-VEHICLE SERVICE
SYSTEM CONFIGURATION DIAGRAM
Canister
Check
valve
Throttle body
Fuel pressure control
valve
Fuel pressure regulator
PCV valve
AirInjector
High temperature sensor*
*: EVOLUTION-IV only