1987 MAZDA 626 Workshop Manual

TUNE-UP PROCEDURE 1C
4BG01 B-006
4BG01B-007
76G01C-237
TUNE-UP PROCEDURE
Turn 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 the electrolyte level.
If the level is too low, add distilled water to the "UP-
PER LEVEL" mark.
3. Check the specific gravity by using a hydrometer.
If the specific gravity reading is 1.200 or less,
recharge the battery, by referring to Section 5.
Air Cleaner Element
Visually check the air cleaner element for being ex-
cessively dirty, damaged or oil.
Clean or replace it if necessary.
Caution
(Wet type)
Do not clean the air cleaner element with com-
pressed air, replace if necessary.
(Dry type)
When cleaning the air cleaner element, blow
dust off from the inside first, then blow off the
outside.
Engine Oil
Check the engine oil level and condition with the oil
level gauge.
Add oil, or change it, if necessary.
4BG01B-009
1C—5

1C TUNE-UP PROCEDURE
Coolant Level
Check that the coolant level is near the radiator inlet
port, and that the level in the reserve tank is between
the FULL and LOW marks.
Add coolant up if the level is low.
Warning
Never remove the radiator cap when the en-
gine is hot.
Wrap a thick cloth around cap and carefully
remove the cap.
4BG01B-010
Water Draining
1. Drain the water from the sedimenter or fuel filter.
If it is difficult to drain the water from the drain plug,
loosen the air bleeding plug.
2. Bleed the air from the sedimenter or fuel filter. (Re-
fer to Section 4D)
76G01C-005
Valve Clearance
1. Remove the cylinder head cover.
2. Set the No. 1 cylinder to compression TDC.
Note
Turn the crankshaft so that the intake and ex-
haust cam lobes face upward.
4BG01B-016
3. Measure the valve clearance of No. 1 cylinder by
using a thickness gauge.
Valve clearance (cold engine)
0.20—0.30 mm (0.008—0.012 in)
0.30—0.40 mm (0.012—0.016 in)
If necessary, adjust the valve clearance referring to
the page 1C—85.
76G01C-006
1C-6

TUNE-UP PROCEDURE 1C
P/S oil pump Checking point
B
Vacuum/^ i V pumpf o ) y ®
v Rear \ camshaft
J
pulley
A-—mP
P/S oil pump \ L^
76G01C-009
Drive Belt
1. Check the drive belt for wear, cracks, or fraying.
Replace if necessary.
2. Check the drive belt deflection by applying moder-
ate pressure (98 N, 10 kg, 22 lb) midway between
the pulleys.
Alternator
Deflection mm (in)
New 8.0-10.0 (0.31-0.39)
Used 9.0—11.0 (0.35—0.43)
If necessary, loosen the idler lock nut and adjust
the belt deflection by turning the adjust bolt.
Tightening torque:
37—52 N-m (3.8—5.3 m-kg, 27—38 ft-lb)
Vacuum pump and P/S oil pump
Deflection mm (in)
Vacuum
pump
New 7.5-8.5 (0.30-0.33) Vacuum
pump Used 8.5-9.5 (0 33-0.37)
P/S oil pump
New 6.5-7.5 (0.26-0 30) P/S oil pump Used 7.0-8.0 (0.28—0.31)
If necessary, adjust the belt deflection as follows.
(1) Loosen the vacuum pump bolts ©and (§).
(2) Lever the vacuum pump outward and apply
tension to the belt.
(3)Tighten the adjust bolt
Tightening torque:
19—26
N
m (1.9—2.6 m-kg, 14—19 ft-lb)
(4)Tighten the mounting bolt
Tightening torque:
37—52
N
m (3.8—5.3 m-kg, 27—38 ft-lb)
A/C compressor
Deflection mm (in)
New 8.5—9.5 (0.33—0.37)
Used 9.5-10.5 (0.37-0.41)
If necessary, loosen the idler lock nut and adjust
the belt deflection by turning the adjust bolt.
Tightening torque:
37—52 Nm (3.8—5.3 m-kg, 27—38 ft-lb)
1C-7

1C TUNE-UP PROCEDURE
Comprex supercharger
Deflection mm (in)
New 4 0-6.0 (0.16—0.23)
Used 8.0-10 0 (0 31-0.39)
If necessary, loosen the idler lock nut and adjust
the belt deflection by turning the adjust bolt.
Tightening torque:
16—23 Nm (1.6—2.3 m-kg, 12—17 ft-lb)
76G01C-011
o
INJECTION TIMING
1. Disconnect the negative battery cable.
2. Release the CSD using the screw driver.
3. Remove the cover on the clutch housing.
4. Turn the flywheel and set the indicator at ATDC.
5. Disconnect the injection pipes from the injection
pump.
76G04D-008
6. Remove the hydraulic head plug from the injec-
tion pump.
7. Mount the SST into the plug hole on the hydraulic
head so the tip of the dial gauge pointer touches
the plunger end of the pump and the dial gauge
indicates approx. 2.0 mm (0.08 in).
76G04D-009
8. Turn the crankshaft slowly counterclockwise to
30-50° BTDC.
9. Make sure the dial indicator pointer no longer
moves by slightly turning the crankshaft.
10. Set the dial gauge scale to Zero at the pointer.
76G04D-010
1C-8

TUNE-UP PROCEDURE 1C
11. Turn the crankshaft clockwise to align the indica-
tor pin at ATDC 1° (RF-CX), ATDC 2° (RF-N)
12. Read the dial gauge.
Cam lift: 0.98—1.02 mm (0.038—0.040 in)
13. If not within the specification, adjust the injection
timing. (Refer to page 4D—24.)
76G04D-011
Idle Speed
1. Warm up the engine to normal operating tem-
perature.
2. Be sure the A/C switch is OFF.
3. Connect a tachometer and check the engine
speed.
Idle speed: 720 ±20 rpm
If the idle speed is not within the specification, adjust
the idle speed referring to Section 4D.
76G01C-014
Exhaust Smoke
Increase and decrease the engine speed several
times and check that black smoke is not emitted.
If there is, refer to Section 4D for the appropriate
procedure.
76G01C-015
1C—9

1C ON-VEHICLE INSPECTION
ON-VEHICLE INSPECTION
If the engine exhibits low power, poor fuel economy,
or poor idle, check the following:
1. Compression
2. Fuel system (Refer to Section 4D)
COMPRESSION
1. Check that the battery is fully charged, Recharge
it if necessary.
76G01C-016
76G01C-017
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 the fuel injection pipes, nozzles, wash-
ers, and corrugate washers.
5. Disconnect the fuel cut valve connector.
Caution
If this is not done, fuel will be injected from
the injection pump while cranking.
6. Connect a suitable cap to the fuel return pipe on
the injection pump.
7. Connect a compression gauge with SST to injec-
tion nozzle hole.
8. Fully depress the accelerator pedal and crank the
engine.
9. Note the maximum gauge reading.
10. Check each cylinder.
Compression pressure kPa (kg/cm2, psi)-rpm
Standard Minimum
2.943 (30, 427)—200 2.649 (27, 384)—200
76G01C-018
Possible Cause
86U01X-022
1C-10

ON-VEHICLE MAINTENANCE (TIMING BELT) 1 C
ON-VEHICLE MAINTENANCE
TIMING BELT
Removal
1. Disconnect the nagative battery cable.
2. Remove in the sequence shown in the figure referring to the removal note for specially marked parts.
76G01C-019
1. Engine side cover
2. A/C and alternator drive belt
3. Crankshaft pulley
4. Left and right timing belt cover
5. Alternator idle pulley
6. Idler pulley
7. No.3 engine mount
8. Timing belt
9. Timing belt tensioner and spring
Note
Loosen the No.3 engine mount nuts and lower the engine to remove the crankshaft pulley.
1C-11

1 C ON-VEHICLE MAINTENANCE (TIMING BELT)
76G01C-020
76G01C-238
Kww
76G01C-021
Removal note
Timing belt
1. Aligh the timing marks of each pulleys.
2. Affix the injection pump pulley to the bracket us-
ing two bolts (35—40 mm, 1.4—1.6 in).
Caution
a) Do not turn in the reverse direction of en-
gine revolution.
b) After removing the timing belt, do not ro-
tate the crankshaft pulley or camshaft
pulley.
3. Make the forward direction arrow on the timing belt.
Note
Direction arrow is to reassemble the timing
belt in the same direction.
4. Loosen the timing belt tensioner bolt.
5. Shift the tensioner outwards as far as possible, and
temporarily tighten it.
6. Suspend the engine with chain block on the front
engine hanger.
7. Remove the No.3 engine mount.
8. Remove the timing belt.
Caution
Do not allow any oil or grease on the timing
belt.
Inspection and Repair
Inspect the following parts. (Refer to page 1C—60,
61).
1. Timing belt
2. Timing belt tensioner and spring
3. Timing belt idler pulley
4. Timing belt pulley
76G01C-022
1C—12