- Spark plug wrench.
- It is recommended to purchase special pliers, such as HAZET 1849, to facilitate disconnection of the spark plug connector.
The following wearing parts are required:
- Four spark plugs. Types of spark plugs are given here.
Removal
Disconnect all plug connections of the spark plugs. The special pliers mentioned above make this procedure easier.
The spark plug niches must be blown out with compressed air to prevent dirt from getting into the cylinders.
Remove the spark plugs with a spark plug wrench and check the condition of the spark plugs. If you have experience, this allows you to draw a conclusion about the condition of the engine. In this case, the following rules apply if the electrodes and the housing:
- are grey in colour = the spark plugs are working satisfactorily, the mixture has the correct ratio;
- are black = the mixture is too rich;
- are light grey in colour = the mixture is too lean;
- oily = spark plug is working intermittently or piston ring seal is poor (check compression).
Check the spark plug insulator for leakage currents. Leakage currents are visible through thin, uneven marks on the surface. If such marks are present, check for cracks in the spark plug insulator. Replace the spark plug if necessary.
Installation
Check the spark gap with a feeler gauge.
New spark plugs usually have the spark gap adjusted correctly, look here.
To adjust the spark gap, you need to bend the side electrode. There is a simple tool for this. You can lightly tap the side of the electrode. You can rest a screwdriver on the edge of the thread and bend the side electrode. You cannot rest a screwdriver on the central electrode.
(The original source is located on the website www.TOYOTAMAN.ru)
Clean the threads on the spark plug body with a clean cloth.
Screw the spark plugs into the cylinder head by hand until they stop. Caution: Do not tilt the spark plug.
Tighten the spark plugs with a torque of 20 Nm.
Note: If you do not have a torque wrench, new spark plugs can be tightened by 90° with a spark plug wrench. Used spark plugs are tightened by 150°. If the spark plugs are tightened too tightly, the threads may be stripped when unscrewed.
Connect the spark plug connectors. Ignition sequence 1-3-4-2.
Check the reliability of the spark plug connections by shaking them.
Checking electrical connections
Check the reliability of the electrical connections, ignition coil and ignition distributor.
Replace damaged contacts.
Clean corroded contacts with a brush or sandpaper and spray with an aerosol.
The contacts should not be wet. Clean the contacts and spray with aerosol.
Bend the ignition cable and check for cracks. If cracks are present, replace the cable.