MAZDA MX-5 1994 Workshop Manual

ENGINE COOLANT COOLANT PROTECTION SPECIFIC GRAVITY COOLANT TEMPERATURE "C (OF) 45UOEX-00 Coolant Protection Caution The engine has aluminum parts that can be dam- aged by alcohol or methanol antifreeze. Do not use alcohol or methanol in the cooling system. Use only ethylene-glycol-based coolant. Use only soft (demineralized) water in the coolant mixture. Water that contains minerals will cut down on the coolant's effectiveness. 1. Measure the coolant temperature and specific gravity with a thermometer and a hydrometer. 2. Determine the coolant protection by referring to the graph shown. If the coolant protection is not proper, add water or cool- ant. Antifreeze solution mixture percentage I Coolant protection I I Above -1 6°C (3°F) 1 65 1 35 1 1.054 1 REPLACEMENT Draining Above -26°C {-15°F) Above -40°C I-40°F} Warning Removing the radiator cap or the coolant drain plug while the engine is running, or when the en- gine and radiator are hot is dangerous. Scalding coolant and steam may shoot out and cause seri- ous injury. If may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press down on the cap-still using a cloth - turn it, and remove it. 1. Remove the radiator cap and loosen the drain plug. 2. Drain the coolant into a container. 3. Flush the cooling system with water until all traces of col- or are gone, then let the system drain completely. 4. Install the drain plug. 55 45 45 55 1.066 1.078 Gartner Banana

E ENGINE COOLANT REFILLING Use the proper amount and mixture of ethylene-glycol based coolant. (Refer to Coolant Protection, page E-5.) 1. Slowly pour the coolant into the radiator up to the coolant filler port. Filling pace: 1.0 L (1.1 US qt, 0.9 Imp qt}/min. max 2. Fill the coolant reservoir up to the FULL level. 3. Fully install the radiator cap. 4. Start the engine and let it idle until it warms up. 5. If the temperature increases beyond normal, there is ex- cessive air in the system. Stop the engine and allow it to cool; then repeat step 1-3. 6. Run the engine at 2,200-2,800 rpm for five seconds; re- peat several times. 7. Stop the engine and allow it to cool. Warning Remove the radiator cap or the coolant filler cap while the engine is running, or when the engine and radiator are hot is dangerous. Scalding cool- ant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press ii down on the cap -still using a cloth - turn it, and remove it. 8. Remove the radiator cap and check the coolant level. If the coolant level has dropped, repeat the procedure from step 1. Gartner Banana

RADIATOR CAP RADIATOR CAP INSPECTION Radiator Cap Valve 1. Remove foreign material (such as water residue) from between the radiator cap valve and the valve seat. 2. Attach the radiator cap to a radiator cap tester (commer- cially available) with the SST. Apply pressure gradually to 73.6-1 02 kPa (0.75-1 .O5 kgf/cm2, 10.7-1 4.9 psi). 3. Wait about 10 seconds. Verify that the pressure has not decreased. PREPARATION L SST Negative Pressure Valve 1. Pull the negative pressure valve to open it. Verify that it closes completely when released. 2. Check for damage on the contact surfaces and for cracked or deformed seal packing. 3. Replace the radiator cap if necessary. 49 9200 145 Adapter set, radiator cap tester Warning Remove the radiator cap or the coolant drain plug while the engine is running, or when the engine and radiator are hot is dangerous. Scalding cool- ant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise to the first stop. Step back while the pressure escapes. When you're sure all the pressure is gone, press down on the cap - still using a cloth - turn it, and remove it. 05UOEX-014 For inspection of radiator cap valve For inspection of radiator cap valve 49 9200 147 Adapter B (Part of 49 9200 145) Gartner Banana

RADIATOR RADIATOR 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 the undercover. 4. Remove in the order shown in the figure. 5. Install in the reverse order of removal. 1. Air intake pipe 5. Coolant fan, condenser fan 2. Radiator hose 6. Radiator 3. Coolant reservoir hose Inspection . . . . . . . . . . . . . . . . . . . . . . below 4. Coolant fan motor connector, condenser fan motor connector INSPECTION Check for the following and repair or replace as necessary. 1. Cracks, damage, and water leakage. 2. Bent fins (repair with a screwdriver). 3. Distorted or bent radiator inlet. Steps After Installation 1. Install the undercover. _i 2. Connect the negative battery cable. 3. Fill the radiator with coolant. (Refer to page E-6 for WARNING and procedure.) Gartner Banana

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