13-1 GROUP 13 FUEL CONTENTS MULTIPORT FUEL INJECTION (MFI) <2.4 L ENGINE> . . . . . . 13A MULTIPORT FUEL INJECTION (MFI) <3.0 L ENGINE> . . . . . . 13B FUEL SUPPLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13C 13A-2 GROUP 13A MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE> CONTENTS GENERAL DESCRIPTION. . . . . . . . . 13A-3 FUEL PUMP CONNECTOR DISCONNECTION (HOW TO REDUCE PRESSURIZED FUEL LINES) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-478 MULTIPORT FUEL INJECTION (MFI) FUEL PUMP OPERATION CHECK . . . . . . 13A-478 DIAGNOSIS . . . . . . . . . . . . . . . . . . . . 13A-5 MULTIPORT FUEL INJECTION (MFI) RELAY TROUBLESHOOTING STRATEGY . . . . . . 13A-5 AND FUEL PUMP RELAY CONTINUITY TROUBLE CODE DIAGNOSIS. . . . . . . . . . 13A-5 CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-479 FAIL-SAFE/BACKUP FUNCTION TABLE . 13A-19 INTAKE AIR TEMPERATURE SENSOR DIAGNOSTIC TROUBLE CODE CHART . . 13A-20 CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-479 SYMPTOM CHART. . . . . . . . . . . . . . . . . . . 13A-22 ENGINE COOLANT TEMPERATURE DIAGNOSTIC TROUBLE CODE SENSOR CHECK . . . . . . . . . . . . . . . . . . . . 13A-479 PROCEDURES. . . . . . . . . . . . . . . . . . . . . . 13A-26 THROTTLE POSITION SENSOR CHECK . 13A-480 SYMPTOM PROCEDURES . . . . . . . . . . . . 13A-339 HEATED OXYGEN SENSOR CHECK . . . . 13A-481 DATA LIST REFERENCE TABLE . . . . . . . 13A-442 INJECTOR CHECK . . . . . . . . . . . . . . . . . . . 13A-483 ACTUATOR TEST REFERENCE TABLE. . 13A-450 IDLE AIR CONTROL MOTOR CHECK AT THE ENGINE CONTROL MODULE (STEPPER MOTOR) CHECK . . . . . . . . . . . 13A-483 (ECM)OR POWERTRAIN CONTROL EVAPORATIVE EMISSION PURGE MODULE (PCM) . . . . . . . . . . . . . . . . 13A-452 SOLENOID CHECK . . . . . . . . . . . . . . . . . . 13A-485 INSPECTION PROCEDURE USING AN EGR SOLENOID CHECK . . . . . . . . . . . . . . 13A-485 OSCILLOSCOPE . . . . . . . . . . . . . . . . . . . . 13A-457 INJECTOR . . . . . . . . . . . . . . . . . . . . . 13A-486 SPECIAL TOOLS. . . . . . . . . . . . . . . . 13A-467 REMOVAL AND INSTALLATION . . . . . . . . 13A-486 ON-VEHICLE SERVICE. . . . . . . . . . . 13A-468 THROTTLE BODY ASSEMBLY . . . . . 13A-488 COMPONENT LOCATION . . . . . . . . . . . . . 13A-468 REMOVAL AND INSTALLATION . . . . . . . . 13A-488 THROTTLE BODY (THROTTLE VALVE AREA) DISASSEMBLY AND ASSEMBLY . . . . . . . 13A-489 CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . 13A-472 THROTTLE POSITION SENSOR SPECIFICATIONS . . . . . . . . . . . . . . . 13A-492 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . 13A-473 FASTENER TIGHTENING BASIC IDLE SPEED ADJUSTMENT . . . . . 13A-474 SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . 13A-492 FUEL PRESSURE TEST . . . . . . . . . . . . . . 13A-475 GENERAL SPECIFICATIONS . . . . . . . . . . 13A-492 SERVICE SPECIFICATIONS . . . . . . . . . . . 13A-493 SEALANT . . . . . . . . . . . . . . . . . . . . . . . . . . 13A-493 MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE> 13A-3 GENERAL DESCRIPTION . G EN ER AL DESC RIPTIO N M1131000100154 The Multiport Fuel Injection System consists of control (IAC) motor according to engine coolant sensors, actuators and the engine control module temperature, A/C, and other electrical load. Thus, (ECM) or powertrain control module (PCM) idle speed is kept at an optimum speed. In addition, . The sensors detect the engine condition. The when the air conditioning switch is turned off and on module controls the system based on signals from while the engine is idling, the IAC motor adjusts the these sensors. The actuators work under the control throttle valve bypass air amount. Thus, idle speed is of the ECM or PCM . The ECM maintained at constant speed regardless of various or PCM carries out activities such as fuel engine load conditions. injection control, idle air control, and ignition timing control. In addition, the ECM or PCM IGNITION TIMING CONTROL has several diagnostic test modes which simplify The ignition power transistor located in the ignition troubleshooting when a problem develops. In primary circuit turns on and off to control primary addition, the ECM or PCM is equipped current flow to the ignition coil. This maintains with several diagnostic test modes which simplify ignition timing at an optimum level regardless of troubleshooting when a problem develops. various engine operating conditions. The ECM or PCM determines the ignition timing FUEL INJECTION CONTROL according to engine speed, intake air volume, engine The ECM or PCM controls injector coolant temperature, and atmospheric pressure. drive times and injector timing to supply the optimum air/fuel mixture to the engine according to the DIAGNOSTIC TEST MODE continually-changing engine operation conditions. A