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Spark plugs - General Information
general description Candle for transferring high voltage generated by the ignition coil, lowered to the electrodes in the combustion chamber, wherein the current produces a spark that provides ignition of the working mixture. Inside the combustion chamber spark subjected to cyclic thermal and barometric effects, moreover, are not the last role played by the climatic factor. One of the main requirements for the spark plug is its operation at a voltage above 30 kV and the ability to resist the destruction of its insulation when subjected to temperatures up to 1000 ?� C. In addition, into the combustion chamber of the candle must have good resistance to high-temperature corrosion. Another important parameter to ensure proper functioning of the spark plug is its heat-removing ability. Since candle undergoes rapid periodic changes in temperature determined by its alternate contact is supplied with the cylinder working with a mixture of cold, then warm up to enormous temperature combustion, its ceramic insulator should be highly resistant to cyclic thermal loads. The typical design of spark plugs The recommended type of spark plugs is determined by, among other things heat range, characterized by the ability to resist thermal stresses candles. Thus, the higher the heat rating, the lower the temperature characteristic of the candle. Temperature characteristics of spark plugs Proper selection of the number of candles on the mantle prevents misfiring as the warm-up time of the engine, and in the state mode of operation. In addition to increasing the stability of the engine speed and improve the performance of its economy to prevent misfire can significantly reduce the concentration of the emission of hydrocarbons (HC). Stability and intensity of sparking candle is determined by its electrode gap. At first glance it is preferable to have a maximum clearance between the central and side electrodes of the plug, as increasing the size of the spark provides reliable combustion air-fuel mixture by increasing the volume of its initial ignition. On the other hand, the excessive size of the gap increases the likelihood that the coil produced by the breakdown voltage is not sufficient to obtain a stable spark discharge under adverse circumstances, especially at the end of the life of the candle. In modern engines, a high degree of compression ignition for sustainable exceptions Misfire richness for the life of the candle should be particularly attentive to the observance of the normalized electrode gap. Replace the spark plugs should be carried out strictly in accordance with the schedule of routine maintenance of the car (see. Section routine maintenance schedule of the Head Current leaving and service), - description of the procedure is given in the same place, in Section Replacing glow. In appearance, the candle can be concluded about the candle, quality management and the mixture state of the engine (pistons, piston rings, etc.). Coal deposits  |
Symptoms: The presence of soot indicates pereobogaschenie air-fuel mixture or low intensity spark. It causes misfiring complicates start and leads to instability of the engine.
Recommendation: Check whether the air cleaner is not blocked is not too high fuel level in the float chamber, if not jammed choke and not too worn contacts. Try to use candles with longer insulator that raises resistance to contamination. |
Oiling  | Symptoms: oily contamination spark causes wear stem seals. The oil enters the combustion chamber through the valve guides or worn piston ring. It causes misfiring complicates start and leads to instability of the engine.
Recommendation: Perform mechanical recovery work and replace candles. |
Overheat  | Symptoms: Porous, white insulator, erosion of electrodes and the absence of any deposits. It leads to a reduction in the life of the candle.
Recommendation: Check whether the requirements of Specifications of the Head of System of an electric motor heat rating established candles, correctly exposed ignition timing is not served there too lean air-fuel mixture leaks vacuum inlet pipeline and whether valves are jammed. Check the coolant level as well, and blockage in the radiator. |
Too early ignition  | Symptoms: Electrodes are melted. The insulator is white, but may be contaminated due to a misfire, or falling into the combustion chamber of foreign particles. It may lead to engine damage.
Recommendation: Check the number of installed glow of candles, the ignition timing, the quality of the mixture (not too depleted), blockage in the cooling system is functioning normally and the lubrication system. |
Electrically conductive gloss  | Symptoms: Insulator has yellowish color and the polished look. It speaks about sudden rise in temperature in the combustion chambers at sharp acceleration. Ordinary deposits while melted, getting kind of lacquer. It leads to misfire at high speeds.
Recommendations: Change candles (colder, while maintaining the driving style). |
The closure of the electrodes  | Symptoms: Waste combustion products enter the inter-electrode space. Solid deposits accumulate, forming a bridge between the electrodes. Leads to failure of the ignition cylinder.
Recommendation: Remove deposits from the electrode area.
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The normal state of candles  | Symptoms: Gray-brown color and easy deterioration of electrodes. Heat range spark for the type of engine and its general condition.
Recommendations: At replacement of candles set the candles of the same type. |
Peploobrazovanie  | Symptoms: Soft brownish deposits on one or both of the spark plug electrodes. The source of their formation are applied additives to oil and / or fuel. Excessive accumulation can lead to isolation of the electrodes and cause misfiring and unstable engine performance during acceleration.
Recommendation: With the rapid accumulation of sediment change stem seals that will prevent oil from entering the combustion chamber. Try to change the brand of fuel. |
Wear  | Symptoms: Rounding electrodes with a small accumulation of deposits on the working end. Color normal. It leads to difficulty starting the engine in cold damp weather and increased fuel consumption.
Recommendations: Change candles on new, the same type. |
Detonation  |
Symptoms: Insulators can be cleaved or cracked. It can cause damage to the insulator as sloppy technique adjustment of a candle backlash. It can cause damage to the pistons. |
Splashing  | Symptoms: After misfire for a long period of time deposits can disintegrating maintaining the operating temperature in the combustion chamber. At high speeds of deposition flakes come off the piston and stick to a hot insulator, causing misfiring.
Recommendations: Replace candles or smooth out and replace the old ones. |
Mechanical damage  | Symptoms may be caused by the ingress of foreign material into the combustion chamber, or occur when the piston stroke about too long candle. Lead to refusal of functioning of the cylinder and piston damage.
Recommendation: Remove from the engine extraneous particles and / or replace sveyai. |
When screwing the candles do not exceed specified in the Specifications of the Head of System of an electric motor maximum permissible tightening force.
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