In newer vehicles, a coil pack replaces the distributor. It is an electronically controlled ignition coil pack regulated by the car’s computer and used to create the spark for each engine cylinder’s spark plug. Generally speaking, coils are much more reliable than distributors because there are no moving parts and because they fire much less frequently than a distributor. Coils typically create a better spark, which in turn produces better combustion and more power in a car’s engine.
How a Coil Pack Works
When creating a spark at the spark plug, the ignition must come from a high-voltage power source so that as much fuel as possible burns in the cylinder. Each time the combustion process is initiated, the coil pack accumulates energy, up to 50,000 to 75,000 volts. When the electronic control module (the car’s computer) sends the signal to the ignition control, the voltage is released from the coil pack through the spark plug wires to the spark plug.
When the spark travels to the spark plug, it jumps across the spark plug gap to ground, causing an explosion of the air-fuel mixture inside the cylinder chamber.
Coil Pack Problems
Usually, if a coil pack is faulty, there will be a loss of ignition or spark in one or more cylinders. This causes what is commonly known as misfires. Misfires can lead to crankshaft drag and typically result in a very rough-running engine.
Common Symptoms of a Faulty Coil Pack
A faulty coil pack will usually exhibit symptoms similar to those of a faulty spark plug. Some of the most common telltale signs that a coil may be faulty include:
- A rough idle
- An engine that is inexplicably louder than usual
- A noticeable lack of power
- A significant drop in RPM when accelerating for no apparent reason
- A check engine light flashing or coming on intermittently
- An active gas warning light when the vehicle has plenty of gasoline
- Exhaust smoke emitting intermittently, instead of a steady flow
How to Test a Coil Pack
Fortunately, there is a simple way to test your vehicle’s coils and ensure they are working as they should. You need to use an ohmmeter to test the coil pack’s continuity. Make sure you have the approximate ohm values for the coil pack. To find this information, search for your car’s engine online or purchase a Chilton or Haynes manual to find out what the mega ohm reading on the coil pack should be.
Coil Packs vs Distributors
While in the past, vehicles used a distributor to transmit the thousands of volts needed to create a spark from the ignition coil to the spark plugs, modern ignition systems now use one coil per spark plug or, in some cases, one coil for two spark plugs. Often, these multiple coils are mounted in a single assembly with multiple terminals, hence the term coil pack.
Coil packs began to be implemented in many vehicles in the late 1990s. The main reason most manufacturers switched to coil packs is that they are more reliable. Many coil packs require no maintenance over a distance of 120,000 to 150,000 miles. Additionally, distributors are very prone to failure if they get wet or if the engine is submerged underwater for a few seconds. Coil packs tend to work even when they have been completely splashed with water.
Besides being more reliable, coil packs are generally credited with providing more power and torque than a common distributor. Because a coil pack typically creates a much more efficient spark, it is also known to provide a slight improvement in fuel efficiency compared to vehicles that use standard distributor caps. Although some modern vehicles still use a distributor system, there are aftermarket upgrades that many car enthusiasts add to improve performance, reduce maintenance, and lower fuel consumption.
Which Coil Pack Works with a Rotary Engine?
Most rotary engines require a different type of ignition coil. Below are two options, one for a standard replacement and another for a high-performance voltage-type coil pack.
Original Equipment Replacement
Beck Arnley is a well-known name in the automotive ignition parts industry. They are favored by many mechanics, especially those who primarily work on import cars. The Beck Arnley 178-8025 Rotary Engine Coil Pack is a direct replacement for original equipment parts on older Mazda cars with a rotary engine. You can expect to pay around $55 for one.
Performance Replacement
M&W Ignition Systems is a fairly well-known name in the import performance market. Their part number PAK005 is a high-performance ignition coil pack for performance enthusiasts who are not afraid to spend a bit more for a high-quality performance part. With prices around $245 for a dual coil pack for direct-fire ignitions, these coil packs will provide years of excellent performance.
When ordering a coil pack for your rotary engine car, you need to know the year and model as well as the engine displacement to ensure you have the correct parts.