The ignition wires draw a high voltage from the ignition coil to the spark plugs. On old engines with trimblers, the wires are supplied with a high voltage from the lid of the distributor to the candles, and they have different lengths for the nearest and distant spark plugs. The wire set also includes an additional wire that connects the central contact of the distributor cover to the ignition coil. In this article we will analyze what wires are, in what cases the ignition wires need to be changed and how to replace the wires.
On engines with a distributed ignition system (DIS), the ignition wires are also used to connect coils with appropriate spark plugs. On some engines, one coil is installed on each spark plug, and on others paired, t. e. One coil for two candles (VAZ).
On new ignition systems, there are no ignition wires, because the coils are installed directly on the spark plugs. But in the coil- there are short wires that connect the coil and candles. In some cases, these wires are part of each coil and cannot be replaced separately.
What are the ignition wires.
There are three main types of ignition wires:
1. Sparkling wires with distributed resistance.
This type has a core made of fiberglass soaked in graphite. This type of wire provides maximum suppression of radio frequency interference (RFI). RFI occurs when high voltage passes through the wire connector. The creation of a controlled amount resistance in the wire (3,000 to 12,000 Ohms) suppresses RFI and prevents sensitive side electronics from false signals that can cause control problems.
One of the disadvantages of this type of wires is that internal resistance creates internal heat. Over time, the resistance increases. And since the resistance increases, this increases the chances of voltage loss.
Until 1980, 95% of all cars were equipped with graphite wires. But concern about emissions and long -term reliability stimulated many Japanese manufacturers to switch to a “magnetic” type of spark plugs of spark plugs.
2. Magnetic type of wires.
This species has a core with a spiral of rafting copper / nickel. RFI is suppressed, first of all, by a magnetic field formed by wires wrapped around the nucleus, and not by the resistance of the wire itself. The magnetic wire has less general resistance than the graphite wire, so it reduces the necessary current for sparking. The main advantage improved strength for a long time.
3. Wires with built -in resistor.
This type of wires has a steel or copper core with a built -in resistor to suppress RFI. This wire is used in many European models.
Isolation of ignition wires.
In the ignition wires, various types of insulation are also used. On premium ignition wires, silicone or EPDM (ethylene is propylene dien monomer) is usually used, some of them have an external coating from EVA (ethylenevini -acetate) for additional thermal resistance and strength.
Under the outer silicone, the EPDM or EVA EVA braid for strength and flexibility, and under this layer isolation from EPDM, which prevents sparking and leakage of the voltage. The magnetic core, as a rule, is surrounded by a silicone layer, which provides additional stability.
Defects of the ignition wires.
Regardless of the type of ignition system or type of ignition wires, a good connection of the wire with other components of the ignition system is necessary, for reliable and trouble -free ignition operation. A poor connection of the wire can create a very high resistance, and the voltage will not reach the candle, or the gap in isolation can take the spark into the ground. In any case, a bad ignition wire will lead to a loss of spark.
Poor ignition wires can lead to a difficult launch of the engine (especially in raw weather), an increase in fuel consumption, vibration, failures with acceleration and increase in emissions.
It is necessary to check the joints of the wires if any of these signs is present, and when replacing candles. If there are no visible damage on the wires, such as carbonization or damaged isolation, free skills or terminals, wires must be replaced. In addition, if an arc is visible, with a running engine, then the wires need to be replaced. The wires should also be replaced if their resistance exceeds the specifications.
Tips for replacing ignition wires.
The ignition wires are of different lengths, so they should coincide with the length of the original wire.
To get started, replace one wire for a while to avoid an error with the order of cylinders (it is very important!). Let’s start with the longest wire and alternately reach the shortest. If you confuse the ignition procedure, the engine will not start or lead to unpleasant consequences. This can lead to damage to the engine, so always double -check the ignition order if you are not sure.
The wires should be directed in the same way as the originals, and supported by special mounts so that they do not touch the exhaust manifold.