1987 MAZDA 626 check engine

ASSEMBLY (CYLINDER BLOCK) 1 A
69G01B-137
Matin
76G01A-075
69G01B-139
Connecting Rod Cap
1. Check the connecting rod bearing clearances us-
ing the same procedure as used for the main bear-
ing oil clearance.
Connecting rod cap tightening torque:
65—69 Nm (6.6—7.0 m-kg, 48—51 ft-lb)
Oil clearance:
0.027—0.067 mm (0.0011—0.0026 in)
Maximum: 0.10 mm (0.0039 in)
Caution
Align the alignment marks on the cap and on
the connecting rod when installing the con-
necting rod cap.
If the oil clearance exceeds specification, grind the
crankshaft and use undersize bearings. (Refer to
page 1A—59.)
3. Check the side clearance of each connecting rod
without the cap installed.
Side clearance:
0.110—0.262 mm (0.004—0.0103 in)
Maximum: 0.30 mm (0.012 in)
If the clearance exceeds the maximum, replace the
connecting rod.
4. Apply a liberal amount of engine oil to the crank-
pin journal and connecting rod bearing.
5. Install the connecting rod cap with the alignment
marks aligned.
Tightening torque:
65—69 Nm (6.6—7.0 m-kg, 48—51 ft-lb)
86U01X-130
1A—67

INSTALLATION 1A
76G01A-099
76G01A-100
Air Cleaner Assembly
1. Install the air cleaner assembly.
Tightening torque:
16—27
N
m (1.6—2.8 m-kg, 12—20 ft-lb)
2. Connect the air flow sensor connector and air in-
take pipe (Fl).
Engine Oil
Add the specified amount and type of engine oil. (Re-
fer to Section 2A.)
Coolant
Close the drain plug, fill the radiator and reservoir tank
with the specified amount and type of coolant. (Re-
fer to Section 3A.)
Check Engine Condition
1. Check for leaks.
2. Perform engine adjustments if necessary.
3. Perform a road test.
4. Recheck the oil and coolant levels.
86U01X-204
1A—99

TUNE-UP PROCEDURE 1 B
76G01A-102
TUNE-UP PROCEDURE
Tune the engine according to the procedures
described below.
Battery
1. Check for corrosion on the terminals, or loose ca-
ble connections.
If necessary, clean the clamps and tighten firmly.
2. Check that the electrolyte level is between the UP-
PER and LOWER marks.
Add distilled water if necessary.
3. Check the specific gravity by using a hydrometer.
If the specific gravity reading is 1.200 or less,
recharge the battery. (Refer to Section 5.)
76G01A-103
Air Cleaner Element
Visually check the air cleaner element for excessive
dirt, damage, or oil. Clean or replace if necessary.
Caution
When cleaning the air cleaner element, blow
dust off from the inside completely first, then
blow from the outside.
76G01B-005
Engine Oil
Check the engine oil level and condition with the oil
level gauge.
Add oil, or change it, if necessary.
4BG01A-010
1B—5

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
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
10. Check the timing belt deflection. If the deflection
is not correct, repeat the adjustment from step 5
above.
Timing belt deflection: 7.5—8.5 mm
(0.30—0.33 in) /98 N (10 kg, 22 lb)
Caution
Be sure not to apply tension other than that
of the tensioner spring.
76G01B-027
Drive belt
Install each drive belt, and check the belt deflection.
(Refer to page 1B—6.)
76G01B-028
Spark plug
1. Apply anti-seize compound or molybdenum-based
lubricant to the spark plug threads.
2. Install the spark plugs.
Tightening torque:
15—23
N
m (1.5—2.3 m-kg, 11—17 ft-lb)
79G01C-021
Steps After Installation
Perform the necessary engine adjustment. (Refer to
TUNE-UP PROCEDURE.)
86U01X-029
1B—15