1987 MAZDA 626 spark plugs

4A
IDLE
SPEED AND
IDLE
MIXTURE
76G04A-059
76G04A-060
76G04A-061

IDLE
SPEED AND IDLE MIXTURE
ADJUSTMENT
Note
a) Before adjusting the idle speed and idle
mixture, be sure the ignition timing, spark
plugs, carburetor float level, etc., are all in
normal operation condition.
b)Turn off all electrical loads.
c) This adjustment must be done while the fan
motor is not operating.
Idle Speed
1. Connect a tachometer to the engine.
2. Warm up the engine, and check that the choke
valve has fully opened.
3. Check the idle speed.
Specification
MTX ATX (in N range)
Specification Others
FE 8Valve Unleaded fuel F6 F8 & FE
Idle speed rpm 800 +6S 850 +5S 950 +5o° 900 +5§
4. If not within specification, adjust the idle speed by
turning the throttle adjust screw.
Caution
After adjusting the idle speed, the dashpot ad-
justment should be checked and adjusted if
necessary.
Idle Mixture
[Except FE 8Valve—Unleaded Fuel]
Adjust the idle mixture as follows, after adjusting the
idle speed.
1. Disconnect the secondary air hoses from the reed
valves and plug them. (If equipped.)
2. Insert an exhaust gas analyzer into the tail pipe and
measure the CO concentration.
CO concentration: 2.0 ± 0.5%
3. If not within the specification, remove the blind cap
from the mixture adjust screw.
76G04A-062
4A—38

4C ESA CONTROL SYSTEM
COMPONENT DESCRIPTION
Component Function Remark
Air flow sensor Detects amount of intake air;
sends signal to engine control unit
Distributor Has Ne and G signal pick-up and distributes high voltage to spark plugs
Engine control unit Detects signals from input sensors and switches; decides best ignition timing
Idle switch Detects when throttle valve fully closed; sends signal to engine control unit Installed on throttle body
Igniter Receives spark signal from engine control unit and generates high voltage in ignition coil
Ignition switch
(ST position) Sends engine cranking signal to engine con-trol unit
Ne signal pick-up Detects crank angle at 180° intervals; sends signal to engine control unit Installed in distributor
Knock sensor (leaded fuel) Detects engine knocking; sends signal to knock control unit
Throttle sensor Detects throttle opening angle; sends signal to engine control unit Installed on throttle body
76G04C-140
TROUBLESHOOTING
Check the condition of the wiring harness and connectors before checking the sensors or switches.
Note
If no problem is found, continue with inspection of the next system of the troubleshooting
Guide. (Refer to page 4C—10 and 11)
Possible cause
Page
Symptom
Air flow sensor Igniter Engine control
unit terminal Knock sensor Possible cause
Page
Symptom
Air flow sensor Igniter
1X
Knock sensor Possible cause
Page
Symptom
4C—103 Refer to section 5 4C—98 4C—109
Hard start or won't start (Cranks OK) 3 1 2 —
Knocking — 1
76G04C-141
4C-76

SPARK PLUG 5
Slow Charge
1. Stop the engine
2. Turn all the accessories off.
3. Remove the negative battery cable.
4. Perform a slow charge (3.5A to 4.5A).
5. Add distilled water if necessary while charging.
6. Charge once more if the specific gravity is under
fully charged gravity.
4BG05X-010
SPARK PLUG
REMOVAL AND INSTALLATION
Note the following points:
1. When the high-tension lead is to be pulled off, be
sure to pull the boot itself, and not the wire.
2. Tighten the spark plugs to the specified torque.
Tightening torque: 15—23 N-m
(1.5—2.3 m-kg, 10.8—16.6 ft-lb)
76G05X-054
Wear and adhesion or cabon
INSPECTION
Check the following points. If a problem is found, re-
place the spark plug.
1. Damaged insulation
2. Worn electrodes
3. Carbon deposits
If cleaning is necessary, use a plug cleaner or a
wire brush. Clean the upper insulator also.
4. Damaged gasket
5. Burnt condition of spark insulator
6. If it is black with carbon deposits, either misfiring
due to improper proportions of gas and air or over-
heating of the plug may have occurred.
Plug gap:
FE (12VALVE) and FE DOHC Leaded fuel
model:
0.70—0.80 mm (0.028—0.031 in)
FE (8VALVE) and FE DOHC Unleaded fuel
model:
1.0—1.10 mm (0.039—0.043 in)
Others:
0.75—0.85 mm (0.030—0.034 in)
76G05X-005
5-9