1994 MAZDA MX-5 Workshop Manual

B TROUBLESHOOTING GUIDE Problem nsufficlent power 4bnormal combustion Engine noise Possible Cause Insufficient compression Malfunction of HLA' Compression leakage from valve seat Seized valve stem Weak or broken valve spring Failed cylinder head gasket Cracked or distorted cylinder head Stuck, damaged, or worn piston ring Cracked or worn piston Malfunction of fuel system Malfunction of ignition system Others Slipping clutch Dragging brakes Wrong size tires Malfunction of engine-related components Malfunction of HLA* Stuck or burned valve Weak or broken valve spring Carbon accumulation in combustion chamber Malfunction of fuel system Malfunction of ignition system Crankshaft- or bearing-related parts Excessive main bearing oil clearance Main bearing seized or heat-damaged Excessive crankshaft end play Excessive connecting rod bearing oil clearance Connecting rod bearing seized or heat-damaged Piston-related parts Worn cylinder Worn piston or piston pin Seized piston Damaged piston ring Bent connecting rod Valves or timing-related parts Malfunction of HLA' Broken valve spring Excessive valve auide clearance Malfunction of cooling system Malfunction of fuel system Others Malfunction of water pump bearing Improper drive belt tension Malfunction of alternator bearing Exhaust gas leakage Malfunction of timina belt tensioner Remedy Replace Repair Replace Replace Replace Replace Replace Replace Refer to section F Refer to section G Refer to section H Refer to section P Refer to section Q Replace Replace Replace Eliminate carbon Refer to section F Refer to section G Replace or repair Replace Replace or repair Replace or repair Replace Replace or repair Replace Replace Replace Replace Replace Replace Replace Refer to section E Refer to section F Refer to section E Adjust Refer to section G Refer to section F Replace Page Tappet noise may occur if the engine has set idle for an extended period. The noise should dissipate after the engine has reached normal operating temperature. (HLA troubleshooting: Refer to page 6-8) Gartner Banana

ENGINE TUNE-UP ENGINE TUNE-UP PREPARATION SST I 49 9200 020 Tension gauge, V-ribbed belt For inspection of ignition timing and idle speed For inspection of drive belt tension ENGINE OIL 49 801 9 9AO System selector Warning Continuous exposure with USED engine oil has caused skin cancer in laboratory mice. Protect your skin by washing with soap and water im- mediately after this work. Inspection 1. Be sure the vehicle is on level ground. 2. Warm up the engine to normal operating temperature and stop it. 3. Wait for five minutes. 4. Remove the dipstick and check the oil level and condi- tion. 5. Add or replace oil if necessary. Note The distance between the L and F marks on the dip- stick represents 0.8 L (0.85 US qt, 0.70 Imp qt}. ENGINE COOLANT Inspection Coolant level (engine cold) Warning Removing 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 can shoot out and cause serious in- jury. It can 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. Verify that the coolant level is near the radiator filler neck. 2. Verify that the coolant level in the coolant reservoir is be- tween the FULL and LOW marks. 3. Add coolant if necessary. Gartner Banana

ENGINE TUNE-UP V-RIBBED BELT PIS or PIS + A/C EQUIPPED AIC EQUIPPED IDLER Coolant quality 1. Verify that there is no buildup of rust or scale around the radiator cap or radiator filler neck. 2. Verify that the coolant is free of oil. d 3. Replace the coolant if necessary. DRIVE BELT Inspection 1. Remove the air intake pipe. 2. Check the drive belts for wear, cracks, and fraying. Re- place 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 be- tween the specified pulleys. Deflection rnrn {in) Drive belt New' Used Limit Alternator 5.5-7.0 6.0-7.5 m.22-0.27) (0.24-0.29) 8.0 (0.31) t" NC 8.0-9.0 9'0-'0.0 11.5 {0.45} {0.32-0.35) {0.36-0.39) A belt that has been on a running engine for less than five minutes. 5. If the deflection is not within specification, adjust it. 6. Install the air intake pipe. Drive belt tension check Belt tension can be checked in place of belt deflection. Check the drive belt tension when the engine is cold, or at least 30 minutes after the engine has stopped. Using the SST, check the belt tension between any two pulleys. Gartner Banana

ENGINE TUNE-UP B 2 ADJUSTING BOLT LOCKNUT Tension N {kgf, lbfl I Drive belt New* Used I Limit I A belt that has been on a running engine for less than five minutes. 45UOBX-011 Alternator PIS, PIS + A/C AIC Adjustment (1) Alternator belt Loosen the alternator bolts @J and @ and adjust the belt deflection by turning the adjusting bolt 0. Tightening torque @: 19-25 N-m {I .9-2.6 kgf.m, 14-18 ft4bf) @: 38-51 N-m (3.8-5.3 kgf.m, 28-38 ft4bf) 491 -745 (50-76, 11 0-1 67) 491-588 (50-60, 11C-132) 49 1-588 (50-60, 11 0-1 32) (2) PIS belt, PIS + A/C belt Loosen the PIS oil pump bolt @ and nuts @ and @ and adjust the belt deflection by turning the adjusting bolt @. Tightening torque @: 3246 N.m (3.24.7 kgf.m, 24-33 ftlbf) @: 37-53 N-m I3.7-5.5 kgf.m, 27-39 ft4bf) 0: 19-25 N-m {I .9-2.6 kgf.m, 14-18 ft4bf) 491 -706 (50-72, 11 0-1 58) 422-490 (43-50, 95-1 10) 422490 {43-50, 95-1 lo} (3) AIC belt If necessary, loosen the lock nut and adjust the belt deflection by turning the adjusting bolt. 343 (35,771 245 {25, 55) 245 {25,55) Tightening torque: 38-51 N.m (3.8-5.3 kgf.m, 28-38 ft.lbf) Gartner Banana

ENGINE TUNE-UP HLA TROUBLESHOOTING GUIDE Problem 1. Noise when engine is started immediately af- ter oil is changed 2. Noise when engine is started after setting approx. one day 3. Noise when engine is started after cranking for 3 seconds or more 4. Noise when engine is started after new HLA is installed 5. Noise continues more than 10 minutes 5. Noise occurs during idle after high speed run- ning Possible Cause Oil leakage in oil passage Oil leakage in HLA Faulty HLA Action Run engine 2000-3000 rpm. If noise stops after 2 second-10 minutes(') HLA is normal. If not, replace HLA. Time required for engine oil to circulate withir engine, includes tolerance for engine oi condition and ambient temperature. Insufficient oil pressure (Refer to page 8-53) Press down HLA by hand. If it does not move, HLA is normal. If it moves, replace HLA. Check oil pressure. If lower than specification, check for cause. Oil pressure; 295-392 kPa I3.0-4.0 kgf/cm2, 43-56 psil-3000 rpm Deteriorated oil Check oil quality. If deteriorated, replace with specified type and amount of oil. Incorrect oil amount IGNITION TIMING, IDLE SPEED Preparation 1. Check the condition of the engine (spark plugs, leaks in hoses, etc.). 2. Make sure all accessories are OFF. 3. Warm up the engine to normal operating temperature. 4. Connect a timing light and a tachometer to the data link connector terminal IG-. When using an externally pow- ered timing light and/or tachometer, connect it to the power connector (Blue: 1 -pin). Measure valve clearance. If more than Omm {0 in}, replace HLA. Check oil level. Drain or add oil as necessary. Caution Grounding the power connector terminal (Blue: 1-pin) will burn out the 20A wiper fuse. 5. Make sure coolant fan does not operate. Gartner Banana

ENGINE TUNE-UP B lgnition Timing 1. Connect the SST and set the TEST SW to "SELF TEST or connect data link connector terminals TEN and GND with a ium~er wire. ~ 4 2. Check the'idle speed, and set it to specification if neces- sary. (Refer to section F.) ldle speed (Neutral): 800-900 (850 + 50) rpm [MT] (P range): 750-450 (800 + 50) rpm [AT] 3. Verify that the timing mark (White) on the crankshaft pulley and the timing belt cover are aligned. lgnition timing: BTDC 9"-11" (1 0" + 1 ") 4. If the marks are not aligned, loosen the crankshaft posi- tion sensor lock bolt, and turn the crankshaft position sensor to make the adjustment 5. Tighten the crankshaft position sensor lock bolt to the specified torque. Tightening torque: 19-25 N.m {I .9--2.6 kgf.m, 1 &-I8 ft-lbf) 6. Disconnect the SST. 7. Verify that the ignition timing is within the specification. Ignition timing: BTDC 6-18" ldle Speed 1. Connect the SST and set the TEST SW to "SELF-TEST or connect data link connector terminals TEN and GND with a jumper wire. 2. Verify that the idle speed is within specification. ldle speed (Neutral): 800-900 (850 + 50) rpm [MT] (P range): 75-50 (800 -e 50) rpm [AT] 3. If the idle speed is not within specification, remove the blind cap from the air adjusting screw and adjust it. 4. After adjusting the idle speed, install the blind cap and disconnect the SST or jumper wire from the data link connector. Gartner Banana

COMPRESSION COMPRESSION If the engine exhibits low power, poor fuel economy, or poor idle, check the following: 1. Ignition system (Refer to section G.) 2. Compression (Refer to page B-10.) 3. Fuel system (Refer to section F.) INSPECTION 1. Check that the battery is fully charged. Recharge it if necessary. (Refer to section G.) 2. Warm up the engine to the normal operating tempera- ture. 3. Turn the engine OFF. 4. Remove all spark plugs. 5. Disconnect the ignition coil connector. 6. Connect a compression gauge to the No.1 spark plug hole. 7. Fully depress the accelerator pedal and crank the en- gine. 8. Record the maximum gauge reading. 9. Check each cylinder, as above. Compression: 1,255 kPa (1 2.8 kgf/cm2, 182 psi)-300 rpm Minimum: 883 kPa (9.0 kgf/cm2, 128 psiF300 rpm Differential limit between cylinders: 196 kPa (2.0 kgf/cm2, 28 psi} 10. If the compression in one or more cylinders is low, pour a small amount of engine oil into the cylinder and re- check the compression. (1) If the compression increases, the piston, piston rings, or cylinder wall may be worn. (2) If the compression stays low, the valve may be stuck or seated improperly. (3) If the compression in adjacent cylinders stays low, the cylinder head gasket may be defective or the cyl- inder head distorted. 11 . Connect the ignition coil connector. 12. Install the spark plugs. Tightening torque: 15--22 N.m (1.5-2.3 kgf.m, 11-16 ftlbf) Gartner Banana

ON-VEHICLE MAINTENANCE B ON-VEHICLE MAINTENANCE PREPARATION L SST 49 DO11 102 Lock tool, crankshaft Shaft (Part of 49 E011 1AO) Collar (Part of 49 E011 1 AO) Warninq For removal / installat ion of timing belt pulley For prevention of engine rotation For prevention of engine rotation 49 EOl 1 105 Stopper (Part of 49 EOll 1AO) 49 EOll 1 A0 Ring gear brake set For prevention of engine rotation For prevention of engine rotation ~onhuous exposure with USED engine oil has caused skin cancer in laboratory mice. Protect your skin by washing with soap and water immediately after this work. 49 SEO1 310 A Centering tool, clutch disc For installation of clutch disc Gartner Banana