1987 MAZDA 626 engine

1A OUTLINE
OUTLINE
The new 626 is equipped with F-series gasoline engine and R-series diesel engine. (R-series diesel
engine — explained in section 1C.) F-series engine has following variations.
1. SOHC model
(1) 12-valve model 2.0 £ = FE engine
(2) 8-valve model 1.6 I = F6 engine
1.8 £ = F8 engine
2.0 £ = FE engine
2. DOHC model (explained in section 1B)
2.0 £ 16-valve = FE DOHC engine
STRUCTURAL VIEW
1A—2

1A TROUBLESHOOTING GUIDE
SPECIFICATIONS
——Engine model
Item ^ FE 12 -valve FE 8-valve F8 F6 ——Engine model
Item ^ FE 12 -valve ECE Except ECE ECE General F6
Type Gasoline, 4 cycle
Cylinder arrangement and number In line, 4 cylinders
Combustion chamber Pentroof Multispherical
Valve system OHC, belt driven
Displacement cc (cu in) 1,998 (121.9) 1,789 (109.1) 1,587 (96.8)
Bore and stroke mm (in) 86.0 x 86.0 (3.39 x 3.39) 86.0 x 77.0 (3.39 x 3.03) 81.0 x 77.0 (3.19 x 3.03)
Compression ratio 9.5 : 1 8.6 : 1 9.0 : 1
Compression pressure kPa (kg/cm2, psi)—rpm
Standard 1,422 (14.5,
206)—280 1,275 (13.0, 185)—270 1,128 (11.5, 164)—270 Compression pressure kPa (kg/cm2, psi)—rpm Minimum 996 (10.2,
144)—280 893 (9.1, 129)—270 790 (8.1, 114)—270
Valve timing
IN Open BTDC 14° 16° 20° 20° 17° 17°
Valve timing
IN Close ABDC 56° 54° 65° 65° 56° 56° Valve timing
EX Open BBDC 69° 54° 65° 65° 64° 64° Valve timing
EX Close ATDC 13° 16° 20° 20° 15° 15°
Valve clearance mm (in)
IN 0; Mainte-nance-free 0.30 (0.012)
Valve clearance mm (in)
EX 0; Mainte-nance-free 0.30 (0.012)
Idle speed rpm
MTX 800 _+5S ... carb., 850 ± 50 ... Fl
Idle speed rpm ATX 900 _+5g ... carb., 850 ± 50 ... Fl 950 _+5§ carb. 850 ±
50
.Fl
Ignition timing BTDC 6° ± 1°
Firing order
1
-3-4-2
76G01A-003
TROUBLESHOOTING GUIDE
Problem Possible Cause Remedy Page
Difficult starting Malfunction of engine-related components
Burned valve Worn piston, piston ring, or cylinder Failed cylinder head gasket
Replace Replace or repair Replace
1A-49
1A-57

1
A—20
Malfunction of fuel system Refer to Section 4
Malfunction of electrical system Refer to Section 5
Poor idling Malfunction of engine-related components Malfunction of HLA Improper valve clearance Poor valve to valve seat contact Failed cylinder head gasket
Replace Adjust Repair or replace Replace

1
A—75 1A-10 1 A—51
1
A—20
Malfunction of fuel system Refer to Section 4
Excessive oil
consumption
Oil working up Worn piston ring groove or sticking piston ring Worn piston or cylinder Replace Replace or repair

1
A—57 1A—57
Oil working down
Worn valve seal
Worn valve stem or guide Replace
Replace
1A—26
1A—49
Oil leakage Refer to Section 2A
76G01A-004
1A—4

TROUBLESHOOTING GUIDE 1 A
Problem Possible Cause Remedy Page
Insufficient power Insufficient compression Malfunction of HLA Improper valve clearance 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
Adjust
Repair
Replace Replace Replace Replace Replace Replace
1A—75 1A—10
1
A—51 1A—49 1A—53
1
A—20 1A—48 1A—57
1
A—57
Malfunction of fuel system Refer to Section 4
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
Improper valve clearance Sticking or burned valve
Weak or broken valve spring Carbon accumulation in combustion chamber
Replace Adjust Replace Replace
Eliminate carbon

1
A—75 1A—10 1A—49 1A—53
Malfunction of fuel system Refer to Section 4
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
1A—65
1
A—65 1A—66 1A—67
1
A—67
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
1A—55
1
A—57
1
A—57
1
A—57 1A—59
Valves or timing related parts Malfunction of HLA* Improper valve clearance Broken valve spring Excessive valve guide clearance Malfunction of timing belt tensioner
Replace Adjust
Replace Replace Replace
1A—75 1A—10 1A—53 1A—49 1A—61
Malfunction of cooling system Refer to Section 3A
Malfunction of fuel system Refer to Section 4
Others Malfunction of water pump bearing Improper drive belt tension Malfunction of alternator bearing Exhaust gas leakage
Replace Adjust Replace Repair
1 A— 7

1
A—48
* 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.
76G01A-005
1A—5

1A TUNE-UP PROCEDURE
76G01A-102
76G01A-103
76G01A-104
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.)
Air Cleaner Element
Visually check the air cleaner element for excessive
dirt, damage, or oil. Replace if necessary.
Caution
Do not clean the air cleaner element with com-
pressed air, replace if necessary.
Engine Oil
Check the engine oil level and condition with the oil
level gauge.
Add oil, or change it, if necessary.

76G01A-019

1A—6

1A TUNE-UP PROCEDURE
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.
86U01X-008
When set
When measured
Drive Belt
1. Check the drive belt for wear, cracks, or fraying.
Replace if necessary.
2. Check the drive belt tension by using the tension
gauge.
Standard belt tension N (kg, lb)

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)

76G01A-006
76G01A-007
Adjusting bolt
3. 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 Nm (3.8—5.3 m-kg, 27—38 ft-lb)

76G01A-019

1A—7

TUNE-UP PROCEDURE 1A
High-Tension Lead
Check the following points. Clean or replace if
necessary.
1. Damaged lead
2. Carbon deposits
86U01X-014
76G01A-012
49 0187 280
76G01A-013
Carburetor Float Level (Carburetor)
1. Run the engine at idle.
2. Check that the fuel level is at the center of the float
level indicator window.
If necessary, adjust the fuel float level. (Refer to Sec-
tion 4A.)
Hydraulic Lash Adjuster (12 valve)
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 exsits, 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 down each rocker arm by
hand while at TDC of compression stroke.
3. If the rocker arm moves down, replace the HLA.
(Refer to page 1A—75.)
76G01A-014

1
A—9

1A TUNE-UP PROCEDURE
No.1 IN No.2 IN
No.1 EX No.3 EX
76G01A-015
Adjust bolt
^N^^^^^Lock nut
SsKs&b ' Valve
Camshaft >Nw clearance
76G01A-016
76G01A-017
Valve Clearance (8-valve)
1. Warm up the engine to the normal operating tem-
perature.
2. With the piston of the No.1 cylinder at TDC of com-
pression stroke.
Adjust the valve clearance as shown in the figure.
Valve clearance (valve side)
IN : 0.30 mm (0.012 in)
EX: 0.30 mm (0.012 in)
3. Turn the crankshaft one full turn so that the piston
of the No.4 cylinder is at TDC of compression
stroke.
Adjust the clearances of the remaining valves.
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: 6° ±
1
° BTDC (at idle speed)
6. If necessary adjust the ignition timing by turning
the distributor.
69G01B-518
1A—10

1A TUNE-UP PROCEDURE
76G01A-105
Idle Speed (Carburetor)
1. Connect a tachometer to the engine.
2. Turn all electric loads OFF.
3. Confirm that the choke valve has fully returned at
idling speed.
4. Check the idle speed. If necessary, turn the throt-
tle adjust screw and adjust the idle speed.
Idle speed
MTX: 800 ±s8 rpm (in neutral)
ATX: 950
Is8
rpm (in "N" range) F6
900 I58 rpm (in "N" range).. FE, F8
Idle Speed (Fl)
1. Connect the tachometer to the engine.
2. Check the idle speed.
Idle speed
MTX: 850 i!°0 rpm (in neutral)
ATX: 850 t55°o rpm (in "N" range)
3. If necessary, remove the blind cap from the throt-
tle body and adjust by turning the air adjust screw.
4. Install the blind cap.
76G01A-018
Idle Mixture (Carburetor)
1. Disconnect the secondary air hoses from the reed
valves and then plug the hoses (if equipped).
2. Connect an exhaust gas analyzer to the vehicle as
shown in the figure and measure the CO concen-
tration.
76G01A-106
3. Remove the blind cap from the mixture adjust
screw.
Note
The blind cap will be broken when it is re-
moved, do not attempt to reinstall it.
76G01A-019
1A—11