1994 MAZDA MX-5 SECTION T

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

ON-VEHICLE MAINTENANCE CYLINDER HEAD GASKET Replacement Warning e Fuel line spills and leaks are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "Fuel Line Safety Procedures" on section F. Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. 1. Disconnect the negative battery cable. 2. Drain the engine coolant. (Refer to section E.) 3. Remove in the order shown in the figure, referring to Removal Note. 4. Install in the reverse order of removal, referring to Installation Note. Gartner Banana

ON-VEHICLE MAINTENANCE -- 1. Air cleaner housing assembly 2. Accelerator cable Installation Note ............. section E ,, 3. Hoses Removal / Installation Note ....... below 4. Harnesses Removal / lnstallation Note . . page El 8 5. Exhaust manifold insulator 6. Water bypass pipe nut Removal Note ............. page El8 7. Timina belt ~&moval/ Installation ....... page 51 2 Removal / lnstallation Note Hoses Disconnect the hoses shown in the figure. 8. Front exhaust pipe 9. Manifold bracket 10. Cylinder head bolt Removal Note ............. page 518 Installation Note ........... page 519 11. Cylinder head Disassembly .............. page 539 Inspection ................. page B-47 ................. Assembly page 6-69 12. Cylinder head gasket 45UOBX-035 Gartner Banana

ON-VEHICLE MAINTENANCE B Installation Note Cylinder head bolt I I 05UOBX-043 Stem After Installation Apply clean engine oil to the bolt threads and seat faces. Install the cylinder head bolts. Tighten the cylinder head bolts in two or three steps in the order shown in the figure. Tightening torque: 76-81 N.m (7.7-8.3 kgf-m, 56-60 ft4bf) 1. pill the radiator with the specified amount and type of engine coolant. (Refer to Section E.) 2. Connect the negative battery cable. 3. Start the engine and check follows: (1) Engine oil and engine coolant leakage (2) Ignition timing, idle speed (Refer to page B-9.) (3) Operation of emission control system 4. Recheck the engine coolant level. Gartner Banana

ON-VEHICLE MAINTENANCE HLA Removal / lnstallation 1. Disconnect the negative battery cable. 2. Drain the engine coolant. (Refer to section E.) 3. Remove in the order shown in the figure, referring to Removal Note. 4. Install in the reverse order of removal, referring to lnstallation Note. 1. Timing belt Removal / Installation ....... page 51 2 2. Crankshaft position sensor Installation Note ............. section G 3. Camshaft pulley Removal Note ............. page 521 Installation Note ........... page 522 4. Camshaft Removal Note ............. page B-21 Installation Note ........... page B-21 5. HLA 1 Removal Note ............. page B-21 Installation Note ........... page B-21 Inspection ................. page B-53 Gartner Banana