1994 MAZDA MX-5 Workshop Manual

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 IGNITION SYSTEM f PREPARATION b SST r I I 49 BO19 9AO For inspection of System ignition timing selector CIRCUIT DIAGRAM CRANKSHAFT POSITION SENSOR SIGNAL w 9 c PCME 3 IGNITION COlL (WITH IGNITER) IGNITION COlL TO (WITH IGNITER) SPARK PLUG I I I 6'5) IGT2 SIGNAL 1 IGNITER - GND 3 1 h - - CRANKSHAFT POSITION SENSOR IGNITION COIL u Note If a timing light is used to check for spark, some lights do not light at Nos.2 and 4 cylinders even if the ignition system is normal. Gartner Banana

IGNITION SYSTEM TROUBLESHOOTING Misfire I 1 Check 1 NO NO 1. Turn ignition switch ON 2. Connect data link connector terminals (TEN) and (GND) with a jumper wire 3. Check if MIL illuminates I Check if resistance of secondary windings is OK Replace ignition coil (Refer to page G-19) (Refer to page G-19) I Refer to section F Check 2 Check if resistance of Replace high-tension lead (Refer to page G-20) (Refer to page G-20) I I Check 3 Check if spark plug is OK ( I Check 4 1 YES I Check PCME terminals (Refer to section F) a 1 G, 1 H (Igniter) 0 2E, 2G (Crankshaft position sensor) Repair or replace (Refer to section F) ( 2F, 20 ass airflow sensor) YES Replace ignition coil (igniter malfunction) 1 Check 1 Check 3 Check 2 PLUG WEAR AND CARBON BUILDUP BURNS DAMAGE AND DETERIORATION DAMAGE 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

IGNITION SYSTEM IGNITION COIL lnspection Secondary coil winding 1. Remove the high-tension leads. u 2. Measure resistance of the secondary coil winding of each coil with an ohmmeter. Secondary coil winding resistance (at 20°C (68°F)): 8.7-1 2.9 kR 3. If not within specification, replace the ignition coil. 45UOGX-030 I I Insulation resistance of case 1. Remove the high-tension leads and disconnect the con- nectors. 2. Use a 500V megger tester to measure the insulation resistance between the primary terminal and the coil case. Resistance : Above 10 MR 3. If not within specification, replace the ignition coil. L I 45UOGX-031 Replacement 1. Disconnect the high-tension leads and ignition coil con- nector. 2. Remove the installation bolts and the ignition coil. 3. Install in the reverse order of removal. L Tightening torque: 19-25 N.m (1.9--2.6 kgf-m, 14--18 ft-lbf) 45UOGX-032 IGNITER Inspection 1. Check the poor connection of ignition coil, high-tension leads and PCME. 2. Check the ignition coil, and high-tension leads. 3. Mesure the voltage of the PCME terminal as follows. (Refer to section F.) 1 G igniter (Nos.1, 4) 1 H igniter (Nos.2, 3) 2E, 2G crankshaft position sensor (SGT) 2F, 20 mass airflow sensor 4. If all are normal, but misfire still occurs, replace the igni- tion coil. Gartner Banana

IGNITION SYSTEM HIGH-TENSION LEAD Removal l Installation Caution - Reinstall the high-tension leads to their original positions. Incorrect installation can damage the leads and cause power loss, and negatively effect electronic components. Inspection Use an ohmmeter to measure the resistance of each 45uo~x-035 lead. Resistance: 16 kQ per 1 .OO m (3.28 ft) Gartner Banana

STARTING SYSTEM G STARTING SYSTEM CIRCUIT DIAGRAM I TROUBLESHOOTING Check 1 1 No Magnetic switch gE only clicks when ignition switch is at START Check starter (Refer to page G-23) Check wire harness Check 2 NO MT . . . . 1. Depress clutch pedal 2. Check if voltage between interlock switch (starter side) and ground is approx. 12V AT . . . . 1. Shift into P or N range Check wire harness 2. Check if voltage between parwneutral switch (starter side) and ground is approx. 12v 1. Turn ignition switch to START position 2. Check if voltage between S terminal and ground is approx. 12V Check 3 1 No Check starter magnetic switch (Refer to page G-27) I I Check wire harness I MT . . . . Check if voltage between interlockswitch (igni- tion switch side) and ground is approx. 12V AT . . . . . Check if voltage between parwneutral switch (ignition switch side) and ground is approx. 12v Check starter interlock switch (Refer to page G-28) Check parwneutral switch (Refer to section K) Gartner Banana