1994 MAZDA MX-5 check 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

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 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 G * ttt I E (HEAT SINK) 05UOGX-034 V RIBBED BELT X 0 X Brush Spring 1. Measure the force of the brush spring with a spring pres- sure gauge. 2. Replace the spring if necessary. Standard force: 3.14.3 N (0.32-444 kgf, 0.71-0.96 Ibf) Minimum: 1.6--2.4 N (0.16-0.24 kgf, 0.36-0.52 Ibf) Note Read the spring pressure gauge at a brush tip projec- tion of 2mm (0.079 in). Rectifier 1. Check for continuity of the diodes with an ohmmeter. I Negative (Black) I Positive (Red) I Continuity 1 I E I I Yes I -- 2. Replace the rectifier if necessary. DRIVE BELT Inspection 1. Remove the intake air pipe. 2. Check the drive belts for wear, cracks, or fraying. Replace if necessary. 3. Verify that the drive belts are correctly mounted on the pulleys. 4. Check the drive belt deflection when the engine is cold, or at least 30 minutes after the engine has stopped. Ap- ply moderate pressure (98 N, 10 kgf, 22 Ibf) midway between the specified pulleys. Deflection mm {in) I Drive belt New Used Alternator PIS, PIS + A/C 5.b7.0 {0.224.27) 8.0-9.0 iO.32-0.35) 6.W7.5 (0.24--0.29) 9.0-1 0.0 {0.36-0.391 Gartner Banana

CHARGING SYSTEM I AIC EQUIPPED I WHEN MEASURED 45UOGX-015 - ADJUSTING BOLT I I 5. Check the drive belt tension with a tension gauge. Note Belt tension can be measured between any pulleys. J Tension N {kgf, Ibf) A belt that has been on a ruining engine for less than five minutes. Alternator 'IS
+ A/C 6. Install the intake air pipe. Used Drive belt Adjustment New* I Caution If a new belt is used, adjust the belt deflection at the midpoint of new belt specification. 491-745 (50-76,110-167) 49 1-588 (50-60, 11 0-1 32) d (1) Alternator belt Loosen the alternator bolts @ and @ and adjust the belt deflection by turning the adjusting bolt 0. 491-706 (50-72,110-158) 422490 (43-50,95--110) Tightening torque @: 19-25 N.m (1.9-2.6 kgf.m, 14-1 8 ft4bf) @: 38-51 N.m (3.8-5.3 kgf,m, 28-38 ft-lbf) (2) PIS belt, PIS + AIC belt Loosen the PIS oil pump bolts @ and @ and nut 0, and adjust the belt deflection by turning the adjusting bolt 0. Tightening torque @: 3246 N.m (3.24.7 kgf.m, 24--33 ft4bf) @: 37-53 N.m (3.7-5.5 kgf,m, 27-39 ft-lbf) 0: 19-25 N.m (1.9-2.6 kgf-m, 14-1 8 ft-lbf) (3) AIC belt Loosen the locknut and adjust the belt deflection by turning the adjusting bolt. Tightening torque: 38-51 N.m (3.8-5.3 kgf-m, 28-38 ft-lbf) Gartner Banana

IGNITION SYSTEM G GND TEN I I I IGNITION TIMING 1. Check the condition of the engine (spark plugs, leaks in hoses, etc.). 2. Verify that all accessories are OFF. 3. Warm up the engine to the normal operating tempera- ture. Note When using an externally powered timing light and/or tachometer connect it to the power connector (Blue: l-pin). Warning Do not ground the power connector. terminal (Blue: l-pin); some fuses will be burned. 4. Connect a timing light and tachometer to the data link connector terminal (IG-). 5. Connect the SST and set TEST SW to "SELF TEST" or connect data link connector terminals TEN and GND with a jumper wire. 6. Check the idle speed, and set it to specification if neces- sary (Refer to section F.) ' Idle speed (rpm):800-900 (MT) 75-50 (AT) 7. Verify that the timing mark (white) on the crankshaft pulley is aligned with the indicator pin. Ignition timing: 9"-11" BTDC (at idle) 8. If the marks are not aligned, remove the ignition coil bracket and push the ignition coil aside for easy access and then loosen the crankshaft position sensor lock bolts, and turn the crankshaft position sensor to make the adjustment. 9. Tighten the crankshaft position sensor lock bolts to the specified torque. Tightening torque: 19-25 N-m (1 3-2.6 kgf~m, l4--19 ft.lbf) 10. After adjusting the ignition timing, disconnect the jumper wire or SST from the data link connector. 11. Increase the engine speed and verify that the ignition timing advances. Gartner Banana

G IGNITION SYSTEM BURNS PLUG GAP DAMAGE AND DETERIORATION DAMAGE SPARK PLUG Removal 1 Installation Caution Pulling on the wire part of the spark plug lead may i/ break it. To remove the lead, pull only on the boot. Caution To avoid breaking the spark plug be sure to fit the socket squarely over it. Tighten to the specified torque. Spark plug tightening torque: 15--22 N-m (1.5--2.3 kgf-m, 11-16 ft-lbf) Spark Test 1. Disconnect the high-tension lead from the spark plug. 2. Connect a new spark plug to the high-tension lead. 3. Hold with insulated pliers approx. 5-10mm (0.20-4.39 in) from a ground. 4. Crank the engine and verify that a strong blue spark is visible. . -.d' Note If a timing light is used to check for spark, some lights do not light at Nos.:! and 4 cylinders even if the igni- tion system is normal. Inspection Check the following and replace the spark plugs as neces- sary. 1. Damaged insulation. 2. Worn electrodes. 3. Carbon deposits. If cleaning is necessary, use a plug cleaner or a wire brush. Wipe upper insulator. 4. Damaged gasket. Plug gap: 1 .O-1 .l mm (0.040-0.043 in) Gartner Banana