1994 MAZDA MX-5 Workshop Manual

THERMOSTAT E THERMOSTAT REMOVAL / INSTALLATION u 1. Disconnect the negative battery cable. 2. Drain the engine coolant. (Refer to page E-5 for WARNING and procedure.) 3. Remove in the order shown in the figure. 4. Install in the reverse order of removal. @) REPLACE TAB MUST BE ASSEMBLED TOWARD THERMOSTAT COVER 1. Thermostat cover 3. Thermostat 2. Thermostat cover gasket Inspection . . . . . . . . . . . . . . . . . . . . . . below INSPECTION 1. Visually check that the thermostat valve is airtight. 2. Place the thermostat and a thermometer in water. 3. Heat the water and check the following: Initial-opening temperature Main: 86.5-89.S°C (1 88--193OF) Sub: 83.5--86.S°C (1 8Sl87OF) Full-open temperature: 100°C (21 2°F) Full-open lift Main: 8.0mm 10.31 in) min. Sub: 1.5mm (0.06 in) min. Steps After installation 1. Connect the negative battery cable. 2. Fill the radiator with coolant. (Refer to page €4 for WARNING and procedure.) u Gartner Banana

WATER PUMP WATER PUMP REMOVAL I INSTALLATION 1. Disconnect the negative battery cable. 2. Drain the engine coolant. (Refer to page E-5 for WARNING and procedure) 3. Remove in the order shown in the figure, referring to Removal Note. 4. Install in the reverse order of removal. 1. Timing belt 4. Water pump Service . . . . . . . . . . . . . . . . . . . . . Section B Inspect for cracks, damaged mounting sur- 2. PIS oil pump face, bearing condition, and leakage. Removal Note . . . . . . . . . . . . . . page E-1 1 If the water pump is damage, replace it. 3. Water hose Do not repair it. 5. Water inlet pipe Gartner Banana

WATER PUMP Stens After Installation 1. connect the neaative batterv cable. Removal Note PIS oil pump 1. Remove the PIS oil pump with the hoses still connected. 2. Position the pump away from the water pump and affix it with wire. 2. Fill the radiator kith coolant: (Refer to page E-6 for WARNING and procedure.) Gartner Banana

COOLANT FAN MOTOR , 45UOEX-022 REPLACEMENT 1. Disconnect the negative battery cable. 2. Remove in the order shown in the figure. 3. Install in the reverse order of removal. COOLANT FAN MOTOR INSPECTION 1. Check that the battery is fully charged. 2. Disconnect the coolant fan motor connector. 3. Connect the battery and an ammeter to the coolant fan motor connector. 4. Verify that current is as specified. Current: below 7.7A 5. If current is not within specification and/or the coolant fan does not turn smoothly, replace the coolant fan motor. 45UOEX-023 1. Air intake pipe 4. Coolant fan motor 2. Coolant fan motor connector 5. Coolant fan cowling 3. Coolant fan Gartner Banana

COOLANT FAN RELAY COOLANT FAN RELAY 2. Apply battery positive voltage between terminals B and D. Check for continuity between terminals A and C. 3. If not as specified, replace the coolant fan relay. 45UOEX-025 INSPECTION 1. Check continuity as shown with an ohmmeter. Terminal A-C B-D Continuity NO Yes Gartner Banana

Before beginning any service procedure. refer to section T of this manual for air bag system service warnings and audio antitheft system alarm conditions . FUEL AND EMISSION CONTROL SYSTEMS INDEX ............................ F- 2 ......................... OUTLINE F- 5 .............. SYSTEM DIAGRAM F- 5 VACUUM HOSE ROUTING DIAGRAM ...................... F- 6 WIRING DIAGRAM ............... F- 7 SPECIFICATIONS ............... F- 8 COMPONENT DESCRIPTIONS ... F- 9 ....... TROUBLESHOOTING GUIDE F- 11 ENGINE CONTROL OPERATION CHART ........................ F- 11 RELATIONSHIP CHART .......... F- 12 USING THIS SECTION ........... F- 13 DIAGNOSTIC INDEX ............. F- 15 SYMPTOM TROUBLESHOOTING . F- 17 PREPARATION ................... F- 75 ............. BASIC INSPECTION F- 75 .................. ADJUSTMENT F- 76 ON-BOARD DIAGNOSIS SYSTEM . . F- 78 DESCRIPTION .................. F- 78 PREPARATION .................. F- 79 DIAGNOSTIC TROUBLE CODE NUMBER ...................... F- 79 ... SWITCH MONITOR FUNCTION F- 95 INTAKE AIR SYSTEM .............. F- 98 COMPONENTS .................. F- 98 SYSTEM OPERATION ............ F-100 THROTTLE BODY ............... F-101 INTAKE MANIFOLD .............. F-102 ACCELERATOR PEDAL AND CABLE ........................ F-103 IDLE SPEED CONTROL SYSTEM ... F-104 DESCRI PTlON .................. F-104 PREPARATION .................. F-105 BAC VALVE ..................... F-105 IDLE AIR CONTROL VALVE ....... F-106 FUEL SYSTEM .................... F-107 DESCRIPTION .................. F-107 PREPARATION .................. F-108 SYSTEM OPERATION ............ F-109 FUEL TANK ..................... F-111 FUEL FILTER .................... F-113 FUEL PUMP .................... F-114 FUEL PUMP RELAY .............. F-117 PRESSURE REGULATOR ........ F-118 FUEL INJECTOR ................ F-119 PRESSURE REGULATOR CONTROL SYSTEM ......................... F-122 PRC SOLENOID VALVE .......... F-123 EXHAUST GAS RECIRCULATION (EGR) ........................... F-124 PREPARATION .................. F-124 .................. DESCRIPTION F-124 SYSTEM OPERATION F-125 ............ EGR SOLENOID VALVE (VACUUM) F-125 EGR SOLENOID VALVE (VENT) ... F-126 ......... EGR FUNCTION SENSOR F-126 ........... EGR CONTROL VALVE F-127 ................ EXHAUST SYSTEM F-128 .................. COMPONENTS F-128 OUTLINE OF EMISSION CONTROL ......................... SYSTEM F-129 ............. STRUCTURAL VIEW F-129 POSITIVE CRANKCASE VENTILATION ................... (PCV) SYSTEM F-130 ' DESCRIPTION .................. F-I ..................... PCV VALVE F-1 ..... FUEL EVAPORATIVE SYSTEM F- .................. DESCRIPTION F- ....... PURGE SOLENOID VALVE F- ........ TWO-WAY CHECK VALVE F- ...... THREE-WAY CHECK VALVE F- ............. FUEL VAPOR VALVE F- .......... CHARCOAL CANISTER F- CATALYTIC CONVERTER SYSTEM . F- .................. DESCRIPTION F- .......... THREE-WAY CATALYST F- AIC CUT-OFF CONTROL SYSTEM . . F- .................. DESCRIPTION F- ........... SYSTEM INSPECTION F- ...................... A/c RELAY F-1 36 ..... DECHOKE CONTROL SYSTEM F-137 .................. DESCRIPTION F-137 ......... COOLANT FAN CONTROL F-138 ....................... OUTLINE F-138 .................. COOLANT FAN F-139 ............... CONDENSER FAN F-139 ........... SYSTEM INSPECTION F-140 ........... COOLANT FAN RELAY F-140 ........ CONDENSER FAN RELAY F-140 ............... CONTROL SYSTEM F-141 .................. PREPARATION F-141 ............. STRUCTURAL VIEW F-142 POWERTRAIN CONTROL MODULE .............. (ENGINE) (PCME) F-143 ........ MASS AIRFLOW SENSOR F-152 CRANKSHAFT POSITION SENSOR F-153 ENGINE COOLANT TEMPERATURE ...................... SENSOR F-154 THROTTLE POSITION SENSOR . . F-154 HEATED OXYGEN SENSOR ...... F-156 MAIN RELAY .................... F-157 ............... CLUTCH SWITCH F-157 NEUTRAL SWITCH .............. F-157 STEERING PRESSURE SENSOR . F-158 45UOFX-001 Gartner Banana

INDEX INDEX 1. Air cleaner housing 5. Idle air control valve Removal 1 Inspection / Inspection . . . . . . . . . . . . . . . . . . page F-106 lnstallation . . . . . . . . . . . . . . . . . page F-99 6. Pressure regulator 2. Throttle body Inspection . . . . . . . . . . . . . . . . . . page F-118 Removal . . . . . . . . . . . . . . . . . . . . page F-99 Replacement . . . . . . . . . . . . . . . page F-119 lnspection . . . . . . . . . . . . . . . . . . . page F-99 7. Fuel injector Installation . . . . . . . . . . . . . . . . . . page F-99 Inspection . . . . . . . . . . . . . . . . . . page F-119 3. Intake manifold Removal . . . . . . . . . . . . . . . . . . . page F-119 Removal . . . . . . . . . . . . . . . . . . . . page F-99 Installation . . . . . . . . . . . . . . . . . page F-121 Installation . . . . . . . . . . . . . . . . . . page F-99 8. PCV valve 4. Accelerator pedal and cable Inspection . . . . . . . . . . . . . . . . . . page F-130 1 lnspection . . . . . . . . . . . . . . . . . . . page F-99 9. Purge solenoid valve Replacement . . . . . . . . . . . . . . . . page F-99 On-vehicle inspection . . . . . . . . page F-132 lnspection . . . . . . . . . . . . . . . . . . page F-132 Gartner Banana

INDEX 10. Charcoal canister lnspection . . . . . . . . . . . . . . . . . . page F-133 11. Powertrain control module (engine) Removal / Installation . . . . . . . . page F-143 lnspection . . . . . . . . . . . . . . . . . . page F-143 12. Crankshaft position sensor Removal . . . . . . . . . . . . . . . . . . . page F-153 lnspection . . . . . . . . . . . . . . . . . . page F-153 lnstallation . . . . . . . . . . . . . . . . . page F-153 13. Mass airflow sensor System inspection . . . . . . . . . . . page F-152 lnspection . . . . . . . . . . . . . . . . . . page F-152 14. Engine coolant temperature sensor Removal . . . . . . . . . . . . . . . . . . . page F-154 lnspection . . . . . . . . . . . . . . . . . . page F-154 Installation . . . . . . . . . . . . . . . . . page F-154 15. Throttle position sensor lnspection . . . . . . . . . . . . . . . . . . page F-154 Adjustment . . . . . . . . . . . . . . . . . page F-155 Replacement . . . . . . . . . . . . . . . page F-156 16. Heated oxygen sensor lnspection . . . . . . . . . . . . . . . . . . page F-156 Replacement . . . . . . . . . . . . . . . page F-156 17. Main relay lnspection . . . . . . . . . . . . . . . . . . page F-157 18. Clutch switch (MT) lnspection . . . . . . . . . . . . . . . . . . page F-157 Replacement . . . . . . . . . . . . . . . page F-157 19. Neutral switch (MT) lnspection . . . . . . . . . . . . . . . . . . page F-157 Replacement . . . . . . . . . . . . . . . page F-158 20. Steering pressure sensor lnspection . . . . . . . . . . . . . . . . . . page F-158 Replacement . . . . . . . . . . . . . . . page F-158 21. Fuel pump relay lnspection . . . . . . . . . . . . . . . . . . page F-117 Replacement . . . . . . . . . . . . . . . page F-117 22. PRC solenoid valve lnspection (On-vehicle) . . . . . . page F-123 lnspection . . . . . . . . . . . . . . . . . . page F-123 23. EGR solenoid valve (Vacuum) lnspection . . . . . . . . . . . . . . . . . . page F-125 24. EGR solenoid valve (Vent) lnspection . . . . . . . . . . . . . . . . . . page F-126 25. EGR function sensor lnspection . . . . . . . . . . . . . . . . . . page F-126 26. EGR control valve lnspection . . . . . . . . . . . . . . . . . . page F-127 Replacement . . . . . . . . . . . . . . . page F-127 27. NC relay lnspection . . . . . . . . . . . . . . . . . . page F-136 28. Coolant fan relay lnspection . . . . . . . . . . . . . . . . . . page F-140 29. Condenser fan relay lnspection . . . . . . . . . . . . . . . . . . page F-140 Gartner Banana