1994 MAZDA MX-5 engine

CONTROL SYSTEM Replacement Replace the neutral switch as shown in the figure. STEERING PRESSURE SENSOR Inspection 1. Disconnect the steering pressure sensor connector. 2. Connect an ohmmeter to the switch. 3. Start the engine and let it idle. Check continuity of the switch while turning the steering wheel. PIS 1 Continuity Turnina Yes " I t ~ot turning I NO 4. If not as specified, replace the steering pressure sensor. Replacement Replace the steering pressure sensor as shown in the figure. 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 . ENGINE ELECTRICAL SYSTEM INDEX ....................................... G- 2 OUTLINE ..................................... G- 3 SPECIFICATIONS ........................... G- 3 TROUBLESHOOTING GUIDE .................. G- 4 CHARGING SYSTEM .......................... G- 6 PREPARATION ............................. G- 6 CIRCUIT DIAGRAM ......................... G- 6 TROUBLESHOOTING ....................... G- 7 BATTERY .................................. G- 8 ALTERNATOR .............................. G-10 DRIVE BELT ................................ G-13 IGNITION SYSTEM ............................ G-15 PREPARATION ............................. G-15 CIRCUIT DIAGRAM ......................... G-15 TROUBLESHOOTING ....................... G-16 IGNITION TIMING ........................... G-17 SPARK PLUG ............................... G-18 IGNITION COIL ............................. G-19 IGNITER ................................... G-19 HIGH-TENSION LEAD ....................... G-20 STARTING SYSTEM ........................... G-21 CIRCUIT DIAGRAM ......................... G-21 TROUBLESHOOTING ....................... G-21 STARTER .................................. G-22 STARTER INTERLOCK SWITCH (MT) ......... G-28 45UOGX401 Gartner Banana

OUTLINE OUTLINE SPECIFICATIONS (i.e. powertrain control module (engine), audio, etc.) *2 With System Selector (49 B019 9AO) test switch at SELF TEST. - Engine Item Starter Ignition system Cylinder Arrangement Battery BP DOHC MT I AT 12, Negative ground S46A24L(S) (32 Ah) Maintenance-free 20.0 A.C. I REAR Voltage V Type and capacity (5-hour rate) 12-65 -. 1 2-70 Drive belt deflection mm {in} Dark current" m A Transistorized (built-in voltage regulator) 14.3-1 4.9 21.5 I0.846) 8 (0.31 1 Ignition timing** BTDC ("CA)lrpm U Alternator 'I Dark current is the constant flow of current while the ignition switch is OFF. 45UoGX-003 New Used 101850 Ignition coil Spark plug FRONT 55-7.0 (0.22-0.27) 6.0-7.5 (0.2H.29) 101800 TY pe Primary coil winding n Secondary coil winding kR Type Plug gap mm {in) Firing order Type Output V-A Regulator type Regulated voltage V TY pe Output V-kW Molded (with igniter) - 8.7-1 2.9 (20°C (68°F)) NGK : BKR5E-11 BKR6E-11 (Standard ... MT) NIPPONDENSO : K16PR-U11 K20PR-U11 (Standard ... MT, AT) 1 .O-1.1 IO.040-0.043) 1-3-4--2 Brush length mm {in) Direct 124.95 17.0 i0.67) 11.5 I0.45) Brush length mm {in} Standard Minimum Coaxial reduction 12-1.4 17.5 i0.69) 12.0 i0.47) Standard Minimum Electronic spark advance (ESA) Powertrain control module (engine) controls spark advance Type Spark advance control Gartner Banana

TROUBLESHOOTING GUIDE TROUBLESHOOTING GUIDE Problem Will not crank Cranks slowly Discharged battery Misfire G-5 Will not crank I Will not crank I Check 1 1 , YES, Check if engine cranks with fully charged battery Check charging system (Refer to page G-7) I NO Check ignition switch (Refer to section T), starter interlock switch (Refer to page G-28) and parWneutral switch (Refer to section K) 45uOOx-OC - Check 1 Check if click is heard from starter magnetic switch when ignition is turned to START Cranks slowly Check starting system (Refer to page G-21) Crank slowly Check 1 Check charging system (Refer to page G-7) I NO ---- Check starting system (Refer to page G-21) Check 1 Gartner Banana

CHARGING SYSTEM G TROUBLESHOOTING Check 1 Check if battery p Check battery (Refer to page G-8) J Check 2 I. Turn ignition switch ON Check wire harness 2. Check if voltage exists at each terminal of alternator Check 3 YES 1. Start engine Check alternator (Refer to page G-10) 2. Check if alternator warning light goes off I YES Check if drive belt t Adjust or replace drive belt (Refer to page G-14) 1 YES I Check for dark current (Refer to page G-3) I Check 1 BATTERY r"; Check 3 I ALTERNATOR WARNING LIGHT Check 2 B+: Battery positive voltage I I I B 1 Approx. 12V 1 Approx. 12V I B+ ON ON (Idle) L S 45UOGX-006 OV Approx. 12V Approx. 1V Approx. 12V B+ B+ Gartner Banana

CHARGING SYSTEM 1. Disconnect the battery cables from the battery. 2. Connect a voltmeter to the battery. BATTERY Warning Hydrogen gas is produced during normal battery d operation. A battery-related explosion can cause serious injury. Keep all flames (including ciga- rettes), heat, and sparks away from the top and surrounding area of open battery cells. Caution To prevent damage to electrical components or the battery, turn all accessories off and stop the engine before performing maintenance or re- charging the battery. Caution Obtain the code number and deactivate the audio anti-theft system before disconnecting the bat- tery. (Refer to section T.) Inspection Caution When disconnecting the battery, remove the neg- ative cable first and install it last to prevent dam- age to electrical components or the battery. Gartner Banana

CHARGING SYSTEM G Battery discharge test capable of reading 0.01V Quick charge for 30 min- utes and recheck voltage elo ow 12.4V Above 12.4V I Replace battery el c Apply test load (see test load chart) to the battery using a battery load tester Record battery positive voltage at the end of 15 seconds; is voltage more than specifica- tion? I Measure open circuit voltage of battery 1 Replace battery I I Below 12.4V Abov'e 12.4V Test load I Battew I Load (A1 I Battery posltive voltage with load I Charge battery ( I Battery OK I Terminal and cable 1. Clean and tighten the battery terminals and cables. 2. Coat the terminals with arease. 3. Inspect for corroded or 6ayed battery cables. 4. Check the rubber protector on the positive terminal for proper coverage. Recharging Warning Before performing maintenance or recharging the battery, turn off all accessories and stop the engine. The negative battery cable must be removed first and installed last. Battery S46A24L(S) Caution Do not remove vent caps. Follow carefully the instructions of the battery charger to prevent overcharging. u Do not recharging over 30 minutes to prevent damage the battery. Slow charge (A) Under 3 - -- Quick charge (A) Max. 20 Gartner Banana

CHARGING SYSTEM B TE S TERMINAL 1. Remove the battery cover. 2. Disconnect the battery cable from the battery. 3. Remove the battery from the vehicle. 4. Place the battery in a pan of the water to prevent it from ,-, over heating, but keep water away from the top of bat- tery. 5. Charge the battery. Replacement Note When replacing the battery, replace it with the same style Mazda genuine battery (with vent manifold). ALTERNATOR Caution Obtain the code number and deactivate the audio anti-theft system before disconnecting the bat- tery. (Refer to section T.) Caution Reversing the battery connections or using high- voltage testers will damage the rectifier. Caution Do not start the engine while the connector is dis- connected from L and S terminals. It can damage the alternator. Note .--,' Positive voltage is always present at alternator B ter- minal. Removal l Installation 1. Disconnect the negative battery cable. 2. Disconnect the steering pressure sensor connector. 3. Disconnect the water thermoswitch connector. 4. Disconnect the IAC valve connector. 5. Remove the intake air pipe. 6. Disconnect the wire and connector from the alternator. 7. Remove the alternator bolts and nut. 8. Remove the alternator. 9. Install in the reverse order of removal. Tightening torque Bolt 0: 38-51 N.m (3.8-5.3 kgf-m, 27-38 ftelbf) Bolt @ : 19-25 N.m j1.9-2.6 kgfem, 14--18 ft-lbf) Nut @I: 9.9--14 N.m (100-150 kgf-cm, 87-1 30 in-lbf) Gartner Banana