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Coil On Plug Boots Cracked Magazine

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The CSI system is a modular design, with nearly all the major ignition system components housed in a single cassette (Fig. 1, page 44). The cassette is mounted directly over the spark plugs, with only connector springs and insulating boots to transfer the ignition energy to the plugs. The cassette houses two ignition coils. Each simultaneously sends ignition energy to two paired cylinders-one cylinder on its exhaust stroke and the other on its compression stroke. Cylinders 1 and 4 are paired as running mates on one coil and cylinders 2 and 3 are paired on the other coil.

coil on plug boots cracked magazine
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Fig. 2 on page 44 illustrates the 1/4 ignition coil firing events. One spark plug in the pair of DIS running mates always fires from the center electrode to the side electrode, while the other fires from the side electrode to the center electrode. One cylinder's firing voltage rises in a negative direction, relative to engine ground, on the way to its final spark plug gap breakdown voltage. It then breaks quickly in a positive direction, back toward ground until the spark line is established. The running mate cylinder's firing voltage rises in a positive direction, relative to engine ground. It then quickly breaks over in a negative direction, back toward engine ground until the spark line is established. The polarity characteristics of the spark breakover events are one part of the information reflected in the CSI signal.

As a DIS ignition coil releases its stored energy, an electric field is created in both secondary circuits of the paired cylinders. This growing electric field simultaneously creates a voltage potential across both spark plug electrode sets. Over a period of 5 to 10 microseconds, this voltage level becomes high enough to reach the spark plug gap breakdown voltage level. Each spark plug gap breakdown level is determined by the impedance value of the individual spark plug gaps. At the breakdown point, the air gap between the spark plugs' electrodes will ionize and quickly conduct current, break over and establish an arc across the electrodes

The spark plug gap impedance is affected by several factors. The greatest variable is the pressure in the cylinder when the spark is generated by the coil. A cylinder on its exhaust stroke has less in-cylinder pressure than a cylinder on its compression stroke.

Remember, a DIS coil releases its energy to two cylinders simultaneously-to one cylinder on its exhaust stroke, to the other on its compression stroke. However, due to the pressure-related uneven plug gap impedances, both spark plug gaps will not break down at the same instant. Under most engine operating conditions, the spark plug gap in the cylinder on the exhaust stroke will break down before the spark plug gap in the cylinder on the compression stroke. The order of the spark plug gap breakover events is reflected in the CSI signal.

The ignition firing voltages are shown in Fig. 4 on page 48, magnified by a time factor of 50 to get a closer look at the firing line characteristics as they're reflected in the CSI signal. When the 1/4 coil fires as cylinder 1 is up on its compression stroke, the No. 4 spark plug will fire first on its respective waste stroke. This cylinder 4 waste firing event will create a high-speed transient breakover voltage change from the positive peak breakdown firing voltage back toward zero volts. This breakover transient voltage is passed across the CSI measuring resistor in the form of a rapid voltage change in a negative direction. Then, a few microseconds later, as cylinder 1 fires on compression, there will be a high-speed transient breakover voltage change from the negative peak breakdown firing voltage back toward zero volts. This breakover transient voltage is passed across the CSI measuring resistor in the form of a rapid voltage change in a positive direction.

The 2/3 coil firing event characteristics are also picked up by the CSI sensor in the same manner as above. As shown in Figs. 4 and 5, the firing voltage for cylinder 3, like cylinder 1, rises in a negative direction, and then breaks over in a positive-going direction. The firing voltage for cylinder 2, like cylinder 4, rises in a positive direction, then breaks over in a negative-going direction. The CSI signal reflects the polarity and timing (and thus the amplitude) of each cylinder's spark plug breakover voltage event.

If cylinder 1 were registering steady misfires at idle, use Chart 1 and inspect for defects such as extremely low compression, intake valvetrain issues resulting in a reduction in cylinder density, a badly arcing plug boot or a shorted/fouled spark plug gap. If cylinder 1 were misfiring randomly or only under load, we would use Chart 2 and inspect for leaking secondary components like a torn plug boot, a cracked spark plug or an externally arcing coil.



If cylinder 4 were registering steady misfires at idle, use Chart 3 and inspect for defects such as an open spark plug connector spring or exhaust valvetrain issues resulting in a reduction in flow out of that cylinder. An excessively large spark plug gap may also be responsible. If misfire is occurring randomly or only under load, use Chart 4 and inspect for defects such as an internally arcing or defective coil.

The amount of platinum or iridium that is actually required to manufacture a spark plug is quite small. A tiny button or piece of wire made of iridium or platinum alloy is welded on the tip of the center and ground electrodes to prevent electrode erosion and wear. Even so, when multiplied by the millions of spark plugs that are produced every year to satisfy the demands of both the vehicle manufacturers and aftermarket, the cost of the metal really adds up.Replacement Plugs
The type of spark plug that works best in a given application depends on a number of variables, including the design of the ignition system itself. Most late model engines have some type of Distributorless Ignition System (DIS) with multiple ignition coils.

Other parts a customer may need when replacing spark plugs on a high-mileage engine include new spark plug wires (if used), new coil over plug boots (if the original boots are cracked, damaged or have carbon tracks) and replacement ignition coils (if the original coils are cracked, misfiring or not producing sufficient voltage for reliable ignition).But what kind of gap gauge should be used to avoid damaging the precious metal electrode?

Spark plugs and boots used to be exposed in the engine bay on the sides of the cylinder heads. As high voltage traveled through the spark plug, it created static electricity. The charge caused pieces of dust and debris to stick to the exposed spark plug. It was normal for the attracted contaminants to make an orange or yellow ring called a corona stain. Most modern engines nestle the spark plugs between the camshafts deep in the head. But, the spark plugs are not totally protected from contaminants.

If a carbon track is found on a spark plug or coil tower, an identical track will be found inside the spark plug boot, as well. If the misfire has been ongoing, the boot could show signs of cracking. If the boot or wire set shows signs of flash over, the boots or wire set should be replaced along with the spark plugs. Failure to change the components together will result in the carbon track transferring from the old component to the new component over time. The problem may be temporarily solved by replacing the spark plugs or ignition wires, but after some driving the problem will be right back and the components will all have carbon tracking on them again. This is one reason why it is always important to replace all secondary ignition components at the same time.

It is also important to look at the seals in the valve cover that seal the spark plug tubes. If the well is filled with oil, it might prevent a comeback if you replace the seals and valve cover gasket. Sometimes, the issue could be a cracked valve cover.

When diagnosing ignition components due to misfire codes, inspect the ignition coils, coil-on-plug boots and spark plugs as a complete system. The leading cause of an ignition coil damage claim is spark plug flash-over. Checking the inside of coil boots during routine plug maintenance can lead to fewer come-backs, less time spent on diagnostic repairs, and a happy customer.

Flash-over leaves tracing or burn marks on the insulator of a spark plug. These marks happen when the ignition coil voltage grounds directly into the spark plug shell; before reaching the spark plug ground electrode to complete combustion. The result is a misfire and damage to either the plug insulator, the ignition coil, plug boot or all of the above. This will likely result in misfires that could lead to engine damage.

Similarly, the coil-on-plug boot will show visible signs of spark plug flash-over. Some of these signs are deterioration, cracking, dry-rotting, melting of the coil-on-plug boot, and marks in the interior of the boot where the flash-over occurred.

It is important to also note that not all spark plugs have corrugated ribs. Some spark plugs feature a smooth insulator which is more susceptible to flash-overs, with or without di-electric grease. Another thing to keep in mind when replacing an ignition coil or coil-on-plug boot, is that di-electric grease is usually pre-applied to the product during manufacturing. Applying it a second time during repair increases the risk of flash-overs and misfires.

Not completing a full inspection of the ignition coil and plug boot when performing spark plug maintenance may result in continued misfiring, which could lead to engine and/or catalytic convertor damage. Inspecting both the ignition coil and spark plug when doing routine maintenance will lead to less come-backs, headaches, and warranty returns.

The breaker point ignition system circuit starts and ends with the battery. When the engine is running the battery is continuously being recharged by an alternator or, on older systems, a generator. Current flows from the positive terminal of the battery to the ignition switch and an ignition coil. The ignition coil is really a transformer that steps up the 12-volt current of the battery to somewhere in the neighborhood of 25,000 volts. In engines of medium to high compression this kind of voltage is necessary to reliably arc across the gap on a spark plug and make enough fire to ignite the fuel/air mixture in a cylinder.
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Coil On Plug Boots Cracked Magazine Sheryll Viola <sheryllviola455@gmail.com> - 2023-12-01 00:56 -0800

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