1994 MAZDA MX-5 ignition

OUTLINE, TROUBLESHOOTING GUIDE OUTLINE SPECIFICATIONS Engine Item Tv~e BP DOHC Gasoline, 4-cvcle . . I -, Dis~lacement ml kc. cu inl I 1.840 (1.840. 11 2) I Cylinder arrangement and number Combustion chamber Valve system Bore x stroke mm {in) I 83.0 x 85.0 (3.27 x 3.35) I In-line, 4-cylinders Pentroof DOHC, belt-driven Com~ression ratio I 9.0 I Compression pressure kPa (kgf/cm2, psi)-rpm .- . 1 open (BTDCO) 1,255 {I 2.8, 182)-300 5 Valve timing TROUBLESHOOTING GUIDE tX Valve clearance Problem .. . -. . Difficult starting ' With System Selector (49 B019 9AO) test switch at SELF TEST. 45uo~x-003 Close (ATDCO) IN mm {in) EX mm {in) Poor idling Close (ABDCO) Open (BBDCO) 14 0: Maintenance-free 0: Maintenance-free Excessive oil consumption 48 56 Possible Cause Malfunction of engine-related components Burned valve Worn piston, piston ring, or cylinder Failed cylinder head gasket Malfunction of fuel system Malfunction of ignition system Malfunction of engine-related components Malfunction of HLA' Poor valve-to-valve seat contact Failed cvlinder head aasket Oil leakage I Refer to section D I I Remedy Malfunction of fuel system Malfunction of ignition system Oil working up Worn piston ring groove or sticking piston ring Worn piston or cylinder Oil working down Worn valve seal Worn valve stem or guide Page Replace Replace or repair Replace Refer to section F Refer to section G Replace Replace or repair Re~lace 8-48 B-53,55 B-1 6 B-20 B-50 B-1 6 Refer to section F Refer to section G Replace Replace or repair Replace Replace B-55 B-53,55 B-39,70 8-48 Gartner Banana

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 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

B ON-VEHICLE MAINTENANCE TIMING BELT Removal / lnstallation 1. Disconnect the negative battery cable. 2. Drain the engine coolant. 3. Remove the under cover. 4. Remove in the order shown in the figure, referring to Removal Note. 5. Install in the reverse order of removal, referring to lnstallation Note. (80-110 kgfmn, 7.9-10.7 Nm 13-17 Nm (125-175 kgfcm, 109-151 In4bf) Nm (kgfm, ft4bf) 45UOBX425 1. Air intake pipe 12. Spark plug 2. Upper radiator hose Removal / Installation ......... section G 3. Water hoses (Connected to thermostat 13. PCV valve housing) 14. Cylinder head cover 4. PIS andlor A/C drive belt 15. Upper timing belt cover Removal 1 Installation ....... page B- 6 16. Middle timing belt cover 5. Alternator drive belt 17. Lower timing belt cover Removal / Installation ....... page 5 6 18. Timing belt 6. Water pump pulley Removal Note ............. page B-13 7. Plate Installation Note ........... page B-14 8. Crankshaft pulley Inspection ................. page 8-58 9. Pulley lock bolt 19. Tensioner, tensioner spring Removal Note ............. page B-13 Installation Note ........... page B-14 /' Installation Note ........... page 51 5 Inspection ................. page 558 10. Pulley boss 20. Idler 11. Ignition coil and high-tension lead Inspection ................. page 8-58 Gartner Banana

ON-VEHICLE MAINTENANCE B Stem After Installation 10. Loosen the tensioner lock bolt to apply spring tension to the timing belt. 11. Tighten the tensioner lock bolt. Tightening torque: 38-51 N-m (3.8-5.3 kgf.m, 28--38 ftlbf) 12. Install the pulley boss and pulley lock bolt. 13. Turn the crankshaft 2 and 116 turns clockwise and verify that the timing marks are correctly aligned. 14. Measure the timing belt deflection by applying moderate pressure 98 N (10 kgf, 22 Ibf) midway between the cam- shaft pulleys. If the deflection is not correct, repeat from Step 10 above. Deflection: 9.0-11.5mm (0.36-4.45 in) at 98 N (10 kgf, 22 Ibf) Pulley lock bolt Hold the crankshaft with the SST and tighten the pulley lock bolt. Tightening torque: 157-166 N.m (16-17 kgf.m, 116-122 ftlbf) 1. till the radiator with specified amount and type of engine coolant. (Refer to section E.) 2. Connect the negative battery cable. 3. Start the engine and check, and if necessary, adjust the ignition timing. Gartner Banana