Secondary Ignition Waveforms and Spark Plug Performance

Secondary Ignition Waveforms and Spark Plug Performance

There are at least 500 components in the modern car engine.

Sponsored by Autolite

Our favorite, and an often-under-rated part, is the spark plug. Spark plugs deliver the electric current from the ignition system in our vehicles to the combustion chamber of a spark-ignition engine, igniting the compressed fuel/air mixture with an electric spark. When thinking about secondary ignition waveforms, many auto pros will immediately think of ignition coils, but they should think of the spark plugs as well.

Secondary ignition waveforms are captured when you record the ignition event from when power is applied to the coil, to the point where the coil oscillates with the remaining energy. This ignition event can happen in 6-10 milliseconds, and one millisecond per division is usually the optimal time base depending on the size of the screen and the type of ignition system you’re running. They can also help determine the overall health of the ignition system components, including the spark plugs and coils.

It is imperative that you can confirm a known healthy secondary ignition waveform for a vehicle, so you can keep track of the wellbeing of the engine. Secondary ignition waveforms are largely influenced by spark plugs and the resistance of their two electrodes, also known as the burn line. The burn line from the secondary ignition waveform is the amount of time the spark is between the two electrodes, which can vary depending on the amount of air and fuel that pass between the two electrodes, and burn lines can tell you a lot about what is happening inside the combustion chamber.

If you experience a very turbulent combustion cycle, you’ll see spikes up-and-down, but if the fuel and air are properly distributed, the line on the graph should be smoother, with a little bit of a jump up and down – but nothing significant. If there is greater than normal resistance in the gap, the burn line may be long, while if there is no resistance with the electrodes being very close together, you will notice a very short burn line.

You can tell when the engine is experiencing a wasted spark just by looking at the burn line. Not only will the length of the line tell you the condition of the spark plug, but it can give you specific indicators about the spark plug – if the spark plug is worn out, damaged or if it needs to be replaced because the electrodes are pinched together.

Autolite has been focused on developing spark plugs since 1935. We have done the research and put in the hours to enhance the performance, durability and ignitability of plugs for domestic and import engines. Our latest advances in technology are our iridium spark plugs, Ultra and XP. These plugs offer the highest level of performance and limited lifetime warranties to show you we mean business. Explore the benefits of our new Iridium UltraÒ spark plugs at autolite.com.

You May Also Like

A Closer Look: Gasoline Direct Injection (GDI)

Gasoline direct injection (GDI) is used on most new vehicles and requires a different approach to diagnosis and service. GDI technology has been an integral part of helping to improve fuel economy while reducing emissions, and can be found on more than half of the U.S. fleet. In fact, the use of GDI engines has

Gasoline direct injection (GDI) is used on most new vehicles and requires a different approach to diagnosis and service. GDI technology has been an integral part of helping to improve fuel economy while reducing emissions, and can be found on more than half of the U.S. fleet. In fact, the use of GDI engines has grown by over 600% since 2010. This means that in the next five years, 42 million more vehicles with GDI will enter the Aftermarket “Sweet Spot” of 6-12 years old, during which their injectors and related parts may need to be serviced or replaced. While GDI systems have proved effective, these systems encounter specific failures and require an understanding of how they work and how to test them when they set a code.

A Closer Look: Electronic Throttle Bodies

A shop’s reputation is affected by things like accuracy of diagnosis, quality of the repair, and friendly service. Equally as important is the quality of the parts installed. If the shop does everything right, and the part fails, the customer will ultimately be upset with the shop. When a new part fails, the customer is

Enhancing Efficiency and Streamlining Operations: The Benefits of Utilizing Nexpart Multi-Seller for Repair Centers

In today’s fast-paced automotive repair industry, staying ahead of the competition is crucial for repair centers to thrive. One key aspect that can significantly impact operational efficiency and customer satisfaction is the availability of OE, Aftermarket, Heavy Duty & Salvage parts. Here are just a few advantages of incorporating Nexpart Multi-Seller, a cutting-edge parts ecommerce

Get your vehicle road trip ready with these summer tips 

Summertime is a great time to take your car out on the open road, but it’s also important to ensure that your vehicle is in tip-top shape. Regular preventative maintenance can help you avoid costly repairs and keep your car running smoothly. Make sure you’re ready with these helpful tips from Delphi Technologies. Chassis The

A Closer Look: Ignition Coils

OE coils are known for their high failure rates. Engine misfires, rough idle, a decrease in power under acceleration, poor fuel economy, and a check engine light are all signs of an ignition coil that has failed. Read along for more technical information on how to diagnose a failed coil, and why the original equipment

Other Posts

BMW Spark Plug Replacement

Here are a few things that you need to know before replacing spark plugs in a BMW.

The Do’s and Don’ts of Installing Spark Plugs

This article discusses the “conscious” steps you should perform during spark plug replacement.

Mayhew Tools Introduces Spark Plug Thread Chaser

This tool is made in USA and is backed by a lifetime warranty.

The Impact of Fuel Type on Engine Performance

When fueling, consider engine design, manufacturer recommendations and usage.