Exhaust MAZDA 626 1987 User Guide

1 A ON-VEHICLE MAINTENANCE (VALVE SEAL)
Installation note
Valve seal
1. Apply engine oil to the inside of the new valve seal.
2. Push it on gently with the SST.
86U01X-049
Valve spring
Cylinder head side
Valve spring
1. (12-valve)
Install the valve spring with the narrower pitch to-
ward the cylinder head side.
(8-valve)
Install the outer valve spring with the narrower pitch
toward the cylinder head side.
2. Install the valve keepers, and tap the end of the
valve stem lightly two or three times with a plastic
hammer to confirm that the keepers are all fully
seated.
76G01A-038
12-valve Rocker arm, rocker arm shaft
1. Remove the rocker arm shafts and camshaft caps.
2. (12-valve)
Assemble the rocker arms and springs to the shaft.
Note
a) The intake side shaft has twice as many oil
holes as the exhaust side shaft.
b) The stepped ends are the rear sides of both
intake and exhaust shafts.
76G01A-039
(8-valve)
Assemble the camshaft caps, rocker arms, and
springs, to the shafts.
Caution
Be sure both rocker arm shaft oil holes (in the
center camshaft cap) face each other.
76G01A-040
1A—30

REMOVAL 1A
1. Battery and battery carrier 13. Three-way solenoid 22. P/S oil pump
2. Air cleaner assembly assembly 23. Engine side cover
3. High-tension lead 14. Canister hose (Fl, Middle 24. Front wheel
4. Accelerator cable East) 25. Tie-rod end
5. Throttle cable (ATX) 15. Heater hose 26. Stabilizer control rod
6. Fuel hose 16. Transaxle harness 27. Lower arm bushing
7. Radiator hose 17. Speedometer cable 28. Driveshaft
8. ATF hose (ATX) 18. Clutch release cylinder 29. Change rod (MTX)
9. Radiator harness (MTX) 30. Extension bar (MTX)
10. Radiator and cooling fan 19. Control cable (ATX) 31. Exhaust pipe
11. Engine harness 20. Drive belt 32. Engine mount
12. Brake vacuum hose 21. A/C compressor and 33. Engine and transaxle
bracket 34. Transaxle
76G01A-046
Removal Note
Fuel hose
Warning
a) Cover the hose with a rag because fuel will
spray out when disconnecting.
b) Keep sparks and open flame away from the
fuel area.
Plug the disconnected hoses to avoid fuel leakage.
76G01A-11E
P/S pump, A/C compressor
Remove the P/S pump and A/C compressor with the
hoses still connected to them, secure the pump and
compressor as shown in the figure.
67U01X-029
Driveshaft
Remove the driveshafts. (Refer to Section 9.) Slide
the SST into the transaxle.
86U01X-060
1A—35

DISASSEMBLY (AUXILIARY PARTS) 1 A
1. Oil level gauge
2. P/S oil pump bracket
3. Secondary air pipe assembly (except
General)
4. EGR pipe (Fl, Unleaded carb.)
5. Exhaust manifold insulator
6. Exhaust manifold assembly
7. Coolant inlet pipe and bypass pipe
8. Engine hanger
9. Alternator
10. Alternator strap and bracket
11. Engine mount bracket
12. Distributor and high-tension lead
13. Spark plug
14. Thermostat and thermostat cover
15. Intake manifold bracket (Fl)
16. Intake manifold assembly
17. Oil filter
18. Oil cooler (8-valve...only ECE, 12-valve)
19. Oil pressure switch
76G01A-047
Disassembly Note
Engine hanger
Remove the exhaust manifold; then connect the SST
to the engine.
76G01A-120
69G01X-000
1A—37

INSPECTION AND REPAIR 1 A
86U01X-082
Valve guide
Cylinder head
76G01A-057
(2) Method No. 2
Measure the valve stem play at a point close
to the valve guide with the valve lifted slightly
off the valve seat.
Clearance
IN : 0.025—0.060 mm (0.0010—0.0024 in)
EX: 0.030—0.065 mm (0.0012—0.0026 in)
Maximum: 0.20 mm (0.0079 in)
7. If the clearance exceeds the maximum, replace the
valve and/or valve guide.
8. Check that the valve guide projection height
(dimension A in the figure). Replace if necessary.
Height:
19.8—20.3 mm (0.780—0.799 in)... 12-valve
19.1—19.6 mm (0.752—0.772 in)...8-valve
Replacement of valve guide
Note
Although the shapes of the intake and exhaust
valve guides are different, use the exhaust
valve guide on both sides as a replacement.
86U01X-214
Removal
1. Gradually heat the cylinder head in water to ap-
prox. 90°C (194°F).

76G01A-131

1A—50

ASSEMBLY (CYLINDER HEAD) 1 A
86U01X-148
86U01X-149
86U01X-150
Camshaft
1. Apply a liberal amount of engine oil to the journals
and bearings.
2. Place the camshaft in position with the dowel pin
facing straight up.
Hydraulic Lash Adjuster (HLA)
1. Pour engine oil into the oil reservoir in the rocker
arm.
2. Apply engine oil to the new HLA.
3. Carefully install the HLA into the rocker arm.
Caution
Be careful not to damage the O-ring when in-
stalling the HLA.
Camshaft Cap, Rocker Arm and Shaft Assembly
1. Assemble the rocker arm and shaft assembly as
shown in the figure.
Note
a) The intake side shaft has twice as many oil
holes as the exhaust side shaft.
b)The stepped ends are the rear of the shafts.
2. Apply silicon sealant to the shaded areas shown
in the figure.
76G01A-140

1 A—75

1 A ASSEMBLY (AUXILIARY PARTS)
76G01A-093
76G01A-094
76G01A-095
Exhaust Manifold Assembly
1. Place the new gaskets in position with the ridge
facing the cylinder head.
2. Install the exhaust manifold assembly.
3. Tighten the nuts in two or three steps.
Tightening torque:
34—49
N
m (3.5—5.0 m-kg, 25—36 ft-lb)
Exhaust Manifold Insulator
Install the exhaust manifold insulator.
Tightening torque:
19—30
N
m (1.9—3.1 m-kg, 14—22 ft-lb)
EGR Pipe
Install the EGR pipe.
Tightening torque:
34—44 Nm (3.5—4.5 m-kg, 25—33 ft-lb)
Secondary Air Pipe Assembly
Install the secondary air pipe assembly.
Tightening torque:
16—23 Nm (1.6—2.3 m-kg, 12—17 ft-lb)
P/S Oil Pump Bracket
Install the P/S oil pump bracket.
Tightening torque:
37—63 Nm (3.8—6.4 m-kg, 27—46 ft-lb)
86U01X-178
1A—90

INSTALLATION 1A
Engine Mount
Install the engine mount.

76G01A-096

86U01X-181
Exhaust Pipe
1. Install the exhaust pipe.
Tightening torque
31—46
N
m
(3.2—4.7 m-kg, 23—34 ft-lb)
(§): 64—89
N
m
(6.5—9.1 m-kg, 47—66 ft-lb)
2. Tighten the bracket bolt.
Tightening torque:
19—25 Nm (1.9—2.6 m-kg, 14—19 ft-lb)
Extension Bar (MTX)
Install the extension bar to the transaxle.
Tightening torque:
31—46
N
m (3.2—4.7 m-kg, 23—34 ft-lb)
Change Rod (MTX)
Install the change rod to the transaxle.
Tightening torque:
16—23 Nm (1.6—2.3 m-kg, 12—17 ft-lb)
1A—93

TROUBLESHOOTING GUIDE 1 B
Problem Possible Cause Remedy Page
Insufficient power 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 Sticking, damaged, or worn piston ring Cracked or worn piston
Replace Repair
Replace
Replace Replace Replace Replace Replace
1B—60 1B—37 1B—35 1B—38 1B-16 1B—34 1B—43 1B—43
Malfunction of fuel system Refer to Section 4C
Others Slipping clutch Dragging brakes Wrong size tires
Refer to Section 6 Refer to Section 11 Refer to Section 12
Abnormal combustion Malfunction of engine-related components Malfunction of HLA Sticking or burned valve
Weak or broken valve spring Carbon accumulation in combustion chamber
Replace Replace Replace
Eliminate carbon
1B-60
1B-35
1B—38
Malfunction of fuel system Refer to Section 4C
Engine noise 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
Replace or repair Replace
Replace or repair Replace or repair Replace
1B-51 1B—51 1B—52 1B—53 1B—53
Piston related parts
Worn cylinder Worn piston or piston pin Seized piston Damaged piston ring Bent connecting rod
Replace or repair
Replace
Replace Replace Replace
1B—41 1B-44 1B—43 1B—43 1B-44
Valves or timing related parts Malfunction of HLA* Broken valve spring Excessive valve guide clearance Malfunction of timing belt tensioner
Replace Replace Replace Replace
1B-60 1B—38 1B—35 1B—47
Malfunction of cooling system Refer to Section 3A
Malfunction of fuel system Refer to Section 4C
Others Malfunction of water pump bearing Improper drive belt tension Malfunction of alternator bearing Exhaust gas leakage
Replace Adjust Replace Repair
1B— 6
1B—34
* Tappet noise may occur if the engine is not operated for an extended period of time. The noise should stop after the engine has reached normal operating temperature. 76G01B-004
1B—4

TUNE-UP PROCEDURE 1 B
76G01B-015
6. If necessary, adjust the ignition timing by turning
the distributor.
Idle Speed
1. Ground the test connector to the vehicle with a
jumper wire.
2. Connect a tachometer to the engine.
3. Check the idle speed.
Idle speed: 750 ± 50 rpm
4. If necessary, remove the blind cap from the throt-
tle body and adjust by turning the air adjust screw.
5. Install the blind cap and disconnect the jumper wire
from the test connector.
Idle Mixture
1. Connect an exhaust gas analyzer to the vehicle.
2. Measure the CO and HC concentration.
CO concentration: 1.5 ± 0.5%
HC concentration: Less than 1,000 ppm
3. If necessary, remove the blind cap from the air flow
meter and adjust by turning the bypass air adjust
screw with SST.
4. Install the blind cap to the air flow meter and dis-
connect the jumper wire from the test connector.
76G01B-016
1B—9

1 B ON-VEHICLE INSPECTION
76G01B-017
86U01X-020
76G01B-018
Possible Cause
ON-VEHICLE INSPECTION
If the engine exhibits low power, poor fuel economy,
or poor idle, check the following points.
1. Ignition system (Refer to Section 5)
2. Compression
3. Fuel system (Refer to Section 4C)
COMPRESSION
1. Check that the battery is fully charged. Recharge
if necessary.
2. Warm up the engine to the normal operating tem-
perature.
3. Turn it off for about 10 minutes to allow the exhaust
manifold to cool.
4. Remove all spark plugs.
5. Disconnect the primary wire connector from the
ignition coil.
6. Connect a compression gauge to No.1 spark plug
hole.
7. Fully depress the accelerator pedal and crank the
engine.
8. Note the maximum gauge reading.
9. Check each cylinder.
Standard compression:
1,422 kPa (14.5 kg/cm2, 206 psi)—290 rpm
Leaded fuel
1,373 kPa (14.0 kg/cm2,199 psi)—310 rpm
... Unleaded fuel
Compression limit:
996 kPa (10.2 kg/cm2, 144 psi)—290 rpm
Leaded fuel
961 kPa (9.8 kg/cm2, 139 psi)—310 rpm
... Unleaded fuel
If compression is low, pour heavy oil into the cylinder and turn the crankshaft several times Check compression once more
»
Is compression increased? Yes 1. Worn piston or piston rings
2. Worn cylinder wall
No
1. Worn piston or piston rings
2. Worn cylinder wall
No 1. Defective cylinder head gasket 2. Distorted cylinder head
Is compression in adjacent cylinder low? Yes
1. Defective cylinder head gasket 2. Distorted cylinder head
Is compression in adjacent cylinder low?
No 1. Improper valve seating
2. Valve sticking in guide
3. Defective cylinder head gasket
86U01X-022
1B—10