1987 MAZDA 626 Workshop Manual

1B TUNE-UP PROCEDURE 1 B
86U01X-008
Coolant Level (Cold engine)
1. Check that the coolant level is near the radiator inlet
port.
2. Check that the level in the coolant reservoir is be-
tween the FULL and LOW marks.
Add coolant if necessary.
Warning
a) Never remove the radiator cap while the en-
gine is hot.
b) Wrap a thick cloth around the cap and care-
fully remove it.
Drive Belt
1. Check that the drive belt is positioned in the pul-
ley groove.
2. Check the drive belt for wear, cracks, or fraying.
Replace if necessary.
3. Check the drive belt tension by using the tension
gauge.
Standard belt tension N (kg, lb)
76G01B-006

Belt New Used
Alternator 589-785 (60-80, 132-176) 491-687 (50-70, 110-154)
P/S 687-883 (70-90,154-198) 589-785 (60-80.132-176)
A/C 687-883 (70-90,154-198) 589-785 (60-80,132-176)

76G01B-007
Adjusting bolt
76G01B-008
4. Check the drive belt deflection by applying moder-
ate pressure (98 N, 10 kg, 22 lb) midway between
the pulleys.
(1) Alternator belt deflection
New : 6—8 mm (0.24—0.31 in)
Used: 7—9 mm (0.27—0.35 in)
If necessary, loosen the alternator mounting
bolts and adjust the belt deflection by turning
the adjusting bolt.
Tightening torque
®: 31—46 Nm (3.2—4.7 m-kg, 23—34 ft-lb)
(§): 37—52 Nm (3.8—5.3 m-kg, 27—38 ft-lb)
(2) P/S belt deflection
New : 8—10 mm (0.31—0.39 in)
Used: 9—11 mm (0.35—0.43 in)
If necessary, loosen the idler pulley lock bolt
and adjust the belt deflection by turning the ad-
justing bolt.
Tightening torque of lock bolt:
37—52 N-m (3.8—5.3 m-kg, 27—38 ft-lb)
1B—6

TUNE-UP PROCEDURE 1 B
76G01A-009
76G01A-010
Wear and adhesion of carbon
Burnt
Damage and
deterioration
Damage
76G01B-118
| © © AU
(3) A/C belt deflection
New : 7—9 mm (0.27—0.35 in)
Used: 8—10 mm (0.31—0.39 in)
If necessary, loosen the A/C mounting bolts
and adjust the belt deflection by turning the ad-
justing bolt.
Tightening torque
(A): 37—52
N
m (3.8—5.3 m-kg, 27—38 ft-lb)
(§): 37—52 Nm (3.8—5.3 m-kg, 27—38 ft-lb)
(4) P/S and A/C belt deflection
New : 7—9 mm (0.27—0.35 in)
Used: 8—10 mm (0.31—0.39 in)
If necessary, adjust the belt deflection using the
same procedure as used for the A/C belt
deflection.
Spark Plug
Check the following points. Clean or replace if
necessary.
1. Damaged insulation
2. Worn electrodes
3. Carbon deposits
4. Damaged gasket
5. Burnt spark insulator
6. Plug gap
Plug gap:
0.7—0.8 mm (0.028—0.031 in)
Distributor Cap
Check the following points. Replace if necessary.
1. Cracks or carbon deposits
2. Burnt or corroded terminals
3. Worn distributor center contact

76G01B-008

1B—7

TUNE-UP PROCEDURE 1 B
High-Tension Lead
Check the following points. Clean or replace if
necessary.
1. Damaged lead
2. Carbon deposits
86U01X-014
i^rrr ' /
49 0187 280
76G01B-011
76G01B-012
Hydraulic Lash Adjuster (HLA)
Note
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.
1. Check for tappet noise. If noise exists, check the
following points.
(1) Engine oil condition and level
(2) Engine oil pressure (Refer to Section 2A)
2. If the noise does not stop, check for movement of
each HLA by pushing it during disassembly.
3. If the HLA moves, replace the HLA. (Refer to page
1B—60.)
Ignition Timing
1. Warm up the engine and run it at idle.
2. Turn all electric loads OFF.
3. Connect a timing light tester.
4. Disconnect the vacuum hose from the vacuum
control, and plug the hose.
5. Check that the ignition timing mark (yellow) on the
crankshaft pulley and the timing mark on the tim-
ing belt cover are aligned.
Ignition timing: 12° ± 1° BTDC
(at idle speed)

76G01B-008

1B—8

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

ON-VEHICLE MAINTENANCE (TIMING BELT) 1 B
ON-VEHICLE MAINTENANCE
TIMING BELT
Removal
1. Disconnect the negative battery cable.
2. Remove in the sequence shown in the figure referring to the removal note for specially marked parts.
76G01A-108
76G01B-020
1. Center cover
2. High-tension lead and spark plug
3. Engine side cover
4. Drive belt
5. Crankshaft pulley
6. Engine mount bracket
7. Upper timing belt cover
8. Lower timing belt cover
9. Baffle plate
10. Timing belt tensioner
11. Timing belt tensioner spring
12. Timing belt
1B—11

ON-VEHICLE MAINTENANCE (TIMING BELT) 1 B
76G01B-021
Removal note
Timing belt tensioner
1. Turn the crankshaft to align the mating marks of
the camshaft pulleys.
Note
For intake side camshaft pulley, align "I"
mark.
For exhaust side camshaft pulley, align "E"
mark.
2. Remove the tensioner.
Timing belt
Mark the timing belt rotation for proper reinstallation
if it is reused.
Caution
Be careful not to allow oil, grease, or water
on the belt.
86U01X-024
Inspection
Inspect the following parts. (Refer to page 1B—46,
47.)
1. Timing belt
2. Timing belt tensioner and spring
3. Timing belt idler pulley
4. Timing belt pulley
5. Camshaft pulley
76G01B-022
1B—12

1 B ON-VEHICLE MAINTENANCE (TIMING BELT)
Installation
Install in the reverse order of removal referring to the installation note.
Torque Specifications 76G01A-109
8—12 N m (80—120 cm-kg, 69—104 In-lb)
Installation note
Timing belt
1. Check that the mark on the timing belt pulley is
aligned with the mating mark.
2. Check that the mating mark of the camshaft pul-
leys are aligned with the seal plate mating marks.
Note
For intake side camshaft pulley, align "I"
mark.
For exhaust side camshaft pulley, align "E"
mark.

76G01B-026

1B—13