General Description

GENERAL INFORMATION

Example of spark plug marking. LETTER CODES IN SPARK PLUG MARKING IDENTIFY THE PLUG TYPE, AND NUMBERS REFER TO.

THE THREAD SIZE AND HEAT RANGE.

R – BUILT-IN RESISTOR FOR SUPPRESSION OF ELECTROMAGNETIC INTERFERENCE.

4 – THREAD DIAMETER 14 mm.

3 – HEAT RANGE.

X – THREAD LENGTH 19 mm.

S – EXTENDED TIP

Spark plug marking code explanation

The ignition system includes the battery, distributor, ignition switch, spark plugs, and low- and high-voltage circuits.

ignition switch, spark plugs, and low- and high-voltage circuits..

Most engines use a contactless distributor with electronic ignition timing control, which combines all elements.

of the ignition system. The ignition coil is located in the distributor cap and.

is connected to the rotor by a brush. Some engines are equipped with a separate distributor and ignition coil..

A magnetoelectric sensor is built into the ignition distributor, which generates.

control pulses and sends them to the input of the electronic ignition module. The sensor consists of a rotor with permanent magnets and an inductive coil. As the.

magnetic pole of the rotor passes the inductive coil, an alternating voltage is induced in the coil.

The electrical signal from the coil is sent to the input of the.

semiconductor module, which controls the current in the ignition coil primary circuit.

(step-up transformer). At certain phases of the voltage change in the.

inductive coil circuit, the primary current decreases sharply.

ignition coil. This generates high voltage in the coil secondary winding, which the distributor delivers to the spark plugs in the firing.

order of the engine cylinders. The distributor contains a capacitor to.

reduce radio interference. Ignition timing is controlled by the ECM.

based on signals from various sensors that monitor engine operating conditions.

If the ECM fails, a backup ignition timing control system is provided. This distributor does not use vacuum or mechanical advance.

regulators..

High-voltage wires consist of a wire conductor impregnated with a.

carbon compound and enclosed in silicone rubber insulation. Wire diameter is.

8 mm. The wire insulation material withstands high temperatures well and provides reliable high-voltage electrical insulation. Silicone rubber boot seals are fitted on the spark plugs. When removing.

the boot, turn the protective cap 1/2 turn. Use caution when connecting a test lamp or other sensors to the spark plug. Do not.

insert anything forcefully between the spark plug boot and the wire, or pierce the.

wire insulation. All connections must be made using special.

adapters connected in parallel with the main circuits. Do not pull on the high-voltage.

wire to remove it from the spark plug terminal. Disconnect the wires by.

applying force to the boot or using a special tool..

On all engines except those with aluminum cylinder heads,.

spark plugs with a conical sealing seat (without sealing washers) are used. The spark plugs have a built-in resistor to reduce.

electromagnetic interference. During normal vehicle operation, the engine runs at various speeds: at idle, and at low, medium, and high engine speeds.

crankshaft. For proper spark plug operation, the engine must be run periodically under full load at high crankshaft speed. This removes carbon and other deposits that build up rapidly.

from engine idling or unsteady operation, which are typical of city driving.

The spark plug center electrode is located in an insulator made of heat-resistant ceramic material. The insulator is sealed in the plug body and prevents charge leakage to ground, which would cause misfiring. Do not mistake a short to ground or.

corona discharge for a breakdown. Corona discharge appears as a steady blue glow on the insulator near the edge of the plug body. Corona discharge results from.

high electromagnetic field strength around the spark plug and does not affect.

ignition system operation. Corona discharge is usually visible only in the.

dark. Corona discharge may leave a clean ring-shaped area on the insulator near the plug body, which is sometimes mistaken for gas leakage between the insulator and the plug body..

The mechanical ignition switch is located on the right side of the steering column under the.

steering wheel. The electrical contact section of the ignition switch is separate from the mechanical locking cylinder.

The electrical switching section and the locking mechanism are connected and operate synchronously.

Spark Plug Troubleshooting

Daewoo Nexia: Spark Plug Troubleshooting

Signs of poor spark plug operation include