
13A-1
GROUP 13A
MULTIPORT FUEL
INJECTION (MFI)
<2.4L ENGINE>
CONTENTS
GENERAL DESCRIPTION. . . . . . . . . 13A-3 ON-VEHICLE SERVICE . . . . . . . . . . 13A-1191
COMPONENT LOCATION . . . . . . . . . . . . . 13A-1191
MULTIPORT FUEL INJECTION (MFI) THROTTLE BODY (THROTTLE VALVE
DIAGNOSIS . . . . . . . . . . . . . . . . . . . . 13A-6 AREA) CLEANING . . . . . . . . . . . . . . . . . . . 13A-1197
TROUBLESHOOTING STRATEGY . . . . . . 13A-6 FUEL PRESSURE TEST . . . . . . . . . . . . . . 13A-1197
DIAGNOSTIC FUNCTION . . . . . . . . . . . . . 13A-6 FUEL PUMP CONNECTOR DISCONNECTION
FAIL-SAFE FUNCTION REFERENCE (HOW TO REDUCE PRESSURIZED FUEL
TABLE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-39 LINES) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-1200
DIAGNOSTIC TROUBLE CODE CHART . . 13A-41 FUEL PUMP OPERATION CHECK . . . . . . 13A-1200
SYMPTOM CHART. . . . . . . . . . . . . . . . . . . 13A-46 MULTIPORT FUEL INJECTION (MFI)
RELAY AND THROTTLE ACTUATOR
DIAGNOSTIC TROUBLE CODE
CONTROL MOTOR RELAY CONTINUITY
PROCEDURES. . . . . . . . . . . . . . . . . . . . . . 13A-50
CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-1202
SYMPTOM PROCEDURES . . . . . . . . . . . . 13A-1011
FUEL PUMP RELAY CONTINUITY
DATA LIST REFERENCE TABLE . . . . . . . 13A-1147 CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-1203
GENERAL SCAN TOOL (GST) MODE 01 INTAKE AIR TEMPERATURE SENSOR
REFERENCE TABLE . . . . . . . . . . . . . . . . . 13A-1158 CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-1203
ACTUATOR TEST REFERENCE TABLE. . 13A-1169 ENGINE COOLANT TEMPERATURE
CHECK AT THE ENGINE CONTROL MODULE SENSOR CHECK . . . . . . . . . . . . . . . . . . . . 13A-1204
(ECU) OR THE POWERTRAIN HEATED OXYGEN SENSOR CHECK . . . . 13A-1204
CONTROL MODULE (PCM) . . . . . . 13A-1171 INJECTOR CHECK . . . . . . . . . . . . . . . . . . . 13A-1207
INSPECTION PROCEDURE USING AN THROTTLE ACTUATOR CONTROL
OSCILLOSCOPE . . . . . . . . . . . . . . . . . . . . 13A-1179 MOTOR CHECK . . . . . . . . . . . . . . . . . . . . . 13A-1207
ENGINE OIL CONTROL VALVE CHECK . . 13A-1208
SPECIAL TOOLS. . . . . . . . . . . . . . . 13A-1189
EVAPORATIVE EMISSION PURGE
SOLENOID CHECK . . . . . . . . . . . . . . . . . . 13A-1208
EVAPORATVE EMISSION VENTILATION
SOLENOID CHECK . . . . . . . . . . . . . . . . . . 13A-1208
EGR VALVE CHECK. . . . . . . . . . . . . . . . . . 13A-1208
Continued on next page
13A-2
INJECTOR . . . . . . . . . . . . . . . . . . . . 13A-1209 FASTENER TIGHTENING
REMOVAL AND INSTALLATION . . . . . . . . 13A-1209 SPECIFICATIONS . . . . . . . . . . . . . . 13A-1215
FASTENER TIGHTENING
THROTTLE BODY ASSEMBLY . . . 13A-1212 SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . 13A-1215
REMOVAL AND INSTALLATION . . . . . . . . 13A-1212 GENERAL SPECIFICATIONS . . . . . . . . . . 13A-1215
SERVICE SPECIFICATIONS . . . . . . . . . . . 13A-1217
ENGINE CONTROL MODULE (ECM) SEALANT AND ADHESIVE . . . . . . . . . . . . 13A-1217
AND POWERTRAIN CONTROL
MODULE (PCM). . . . . . . . . . . . . . . . 13A-1214
REMOVAL AND INSTALLATION . . . . . . . . 13A-1214
MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>
GENERAL DESCRIPTION
13A-3
GENERAL DESCRIPTION
M1131000102246
. .
The Multiport Fuel Injection System consists of sen- IDLE AIR CONTROL
sors, actuators and the engine control module (ECM) The idle speed is kept at the optimum speed by con-
or the powertrain control module (PCM) trolling the amount of air that passes through the
. The sensors detect the engine condition. The throttle valve in accordance with changes in idling
ECM or the PCM controls the system conditions and engine load during idling.
based on signals from these sensors. The actuators The ECM or the PCM drives the throt-
work under the control of the ECM or the tle actuator control motor to keep the engine running
PCM . The ECM or the PCM car- at the pre-set idle target speed in accordance with
ries out activities such as fuel injection control, throt- the engine coolant temperature and A/C and other
tle valve opening control, idle air control, and ignition electrical load. In addition, when the air conditioning
timing control. In addition, the ECM or the switch is turned off and on while the engine is idling,
PCM has several diagnostic test modes which the throttle actuator control motor adjusts the throttle
simplify troubleshooting when a problem develops. valve pass-through air amount according to the
. engine load conditions to avoid fluctuations in the
FUEL INJECTION CONTROL engine speed.
The ECM or the PCM controls injector .
drive times and injection timing to supply the opti- IGNITION TIMING CONTROL
mum air/fuel mixture to the engine according to the The ignition power transistor located in the ignition
continually-changing engine operation conditions. A primary circuit turns on and off to control primary cur-
single injector is mounted at the intake port of each rent flow to the ignition coil. This maintains ignition
cylinder. The fuel pump supplies pressurized fuel timing at an optimum level regardless of various
from the fuel tank to the fuel injectors. The fuel pres- engine operating conditions. The ECM or the
sure regulator controls the fuel pressure. Thus, the PCM determines the ignition timing according
regulated fuel is distributed to each injector. Fuel is to engine speed, intake air volume, engine coolant
normally injected for each cylinder every two rota- temperature, and atmospheric pressure.
tions of the crankshaft. The firing order is 1-3-4-2.
Each cylinder has a dedicated fuel injector. This is .
called "multiport". The ECM or the PCM DIAGNOSTIC TEST MODE
provides a richer air/fuel mixture by carrying