Sparkling candles at the final stage of the ignition system. The spark plugs produce a spark to light the fuel mixture. With a bad or weak spark, the engine works with interruptions, consumption, traction loss increases, and the motor may not even start.
The spark is created when the high voltage supplied from the ignition coil slips between the electrodes of the candle. The high pulse voltage from the coil is supplied to the electrode in the center, ionizes the air between the electrodes (air gap) and forms a spark (arc). The initial voltage required for the formation of a spark can vary from 4000 to 28,000 volts, depending on the clearance between the electrodes, the load on the engine and the compression degree increases the required voltage. Sparks life, about milliseconds, but this is enough to ignite the mixture.
The emergence of a spark occurs exactly coincides with the position of the piston, as it approaches, in the upper dead point on the compression tact. On most engines, the spark occurs earlier by several degrees before the piston reaches the upper dead point. If the spark occurs too early, then an explosion of the mixture will occur when the piston has not yet risen to the upper dead point and this will lead to power loss. It can also cause damage to the engine from “detonation”. If the spark occurs too late, it also leads to power loss. The sparking time is controlled by a computer and ignition module, and not the spark plugs, so the early or later ignition will indicate the problems of the sensor or module.
Diagnostics by spark plugs.
If the engine is untwisted, but does not start, one of the first things that you must check is a spark. If there is no spark in any cylinder, then this usually indicates problems with the ignition (coil, ignition module, crankshaft sensor, etc. D.).
If the engine works, but with interruptions, one or more spark plugs can be worn out or polluted, or pierce one or more ignition candles. To diagnose this kind of problem, oscilloscope is required. With increased voltage consumption in one cylinder, it may indicate excessive resistance in the wire connectors, strongly worn or improper gap of the spark plug (too large). With reduced voltage consumption in one cylinder, it may indicate a short circuit of the ignition wire, or contaminated or damaged spark plugs.
Pollution (cargo) is the cause of the number one to replace the spark plugs. Candles with a large gap should also be replaced for prevention, as this leads to a gradual increase in the ignition voltage. The gap of the standard spark plug increases from 0. 016 mm up to 0, 032 mm for every 1,500 kilometers of ordinary driving, and this voltage consumption grows about 500 volts for every 15,000 to 20,000 kilometers of mileage. Therefore, if you do not change candles for a long time, then this can lead to problems with the ignition system.
With one polluted spark plugs, you lose up to 25% of the engine power, in the four -cylinder engine. The contaminated candle also causes a significant increase in fuel consumption and emissions (more than enough to light up the OBD 2 indication light).
Freight is formed if oil seeps into the cylinders. With the wear of the oil seals and guides, the oil is sucked into the combustion chamber. Thick black deposits on a candle and inlet valve indicates such problems. Worn -out or broken rings or damage to the cylinder wall can also allow oil to penetrate the combustion chamber.
The long operation of the car is idling and / or short trips, can also lead to soot. This is because the motor does not heat up enough to burn the deposits.
Black deposits can come from “carbon pollution”. The main reason is a rich fuel mixture. On old carburetor engines, the problem in the carburetor. On engines with fuel injection, the problem can be in nozzles, a faulty oxygen sensor or a coolant sensor that gives the engine control command to work in a closed cycle.
White Nar means that coolant gets into the cylinders. In most cases, the blocking of the block head is broken.
The replacement of the spark plugs will not solve any of these problems, and the new candles will most likely comprehend the same fate if the main problem is not identified and not eliminated.
“Thermal range” of the spark plug.
The “thermal range” of the spark plug determines how the candle works at operating temperature. If the thermal range is selected correctly, for this type of engine, the candle will work quite hot, under normal movement conditions, to burn pollution before they can cause problems. In addition, the candle will not overheat and become a source of premature fuel fire, causing damage to the ignition and detonation. If the thermal range is too cold, the carpet can form faster than it is burned.
For this reason, always follow the instructions of the manufacturer of the car when choosing spark plugs. In the engine with two candles on the cylinder, it may turn out that candles are identical to the outside, but have completely different heat ranges.
It should be noted that there are situations when it makes sense to switch to candles hotter or colder than recommended. The transition to slightly hot spark plugs can help reduce pollution in the old engine that consumes oil for an engine that works a lot of time at idle or is used for short trips. But hot candles should not be used if the engine has problems with contamination. To increase the performance of engines (engine that operate under load or at high speeds for long periods of time), the transition to candles is slightly colder, can minimize the risk of early ignition and detonation. Despite this, a cold candle can increase the risk of pollution during prolonged work at idle and control at low speed.
Many candles have a very wide thermal range, since manufacturers use a copper core or platinum central electrode.
Replacement of spark plugs.
It is recommended to replace standard spark plugs every 30,000 45,000 kilometers. But most reinforced suppositories have special wear -resistant electrodes of platinum, iridium, nickel of ite or other alloys that minimize electrodes erosion. Such candles serve 100,000 kilometers, almost without wear of electrodes. Despite this, they still accumulate soil if the engine has problems with oil consumption or an excessive amount of time at idle.
Reinforced candles are a good solution for many engines, but not the best choice for old engines that “eat” oil.
One of the manufacturers of candles said that candles with platinum electrodes are heated more than standard electrodes. This can increase the risk of early ignition and detonation in some engines with turbocharges. For such engines, a standard candle with a cold heat range can be a safe choice.
There is also a wide range of configurations of electrodes presented on the market. Each manufacturer claims certain advantages in performance for their specific design. This is a decrease in electrode wear, or increasing the reliability of ignition.
Some of these spark plugs (as well as standard) have several electrodes (two, three or four grounding electrodes). Spark plugs with more than one side electrode-only one spark for the cycle will be made of only one spark. But in one of the four ways, which increases the likelihood of obtaining a good spark. The presence of more than one side electrode also distributes wear to minimize electrodes erosion. Some of these candles have a self -cleaning effect.
There is an ignition prize costs additional money? They, if they can provide a long service life of the plugin, reduce the need for maintenance or increase the overall performance of the ignition. Candles, in many front -wheel drive cars and minibuses with V6 engines, is very difficult to replace. The installation of reinforced candles can relieve the trouble associated with the subsequent replacement, t. To. The frequency of the replacement increases.
When replacing the spark plugs, wait until the engine has cooled. The engine should be approximately at room temperature, not hot. This is very important with aluminum cylinder heads, as it reduces the risk of damage to the threads in the cylinder heads when the candles are twisted (aluminum is much softer than the metal than cast iron).
When installing new candles, always follow the recommendations of the car manufacturer, according to the moment of tightening.
Pay attention to the condition of the wires and tips of the spark plugs. Make sure the wires are properly salted with candles (cylinder work procedure). Also look so that the wires do not contact with a hot exhaust manifold.