Understanding Dwell Time in Electronic Ignition Systems

In summary, dwell time refers to the amount of time the ignition coil primary has current running through it in an electronic ignition system. It is a balance between charge time for the coil and the actual dwell time. If the dwell time is too short, the current in the primary coils may not have built up enough magnetic energy to produce a strong spark. This can lead to issues with the ignition system.
  • #1
Andy
73
12
Hey people, been getting very annoyed for the past few hours over this one been looking through all my textbooks and all over the net but can't find a decent explanation of dwell time. Here's my question, Explain dwell time in the context of electronic ignition systems (non-contact breaker points system)

Need help asap before i smash this keyboard through the monitor.

Aploagies for posting it twice but i really need help quickly.
 
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  • #2
The basic definition I know of is that dwell is the time that the ignition coil is delivering the power to the spark plug. It's always a balance between charge time for the coil and the dwell. I know this is pretty general, so if you were looking for anything more specific, let us know.
 
  • #3
Nope that's good, that's pretty much exactly what i just managed to find after many hours of looking. Thank you.

Don't you just hate the internet for providing very vague answers to whatever it is that you looking for?
 
  • #4
FredGarvin said:
The basic definition I know of is that dwell is the time that the ignition coil is delivering the power to the spark plug.
That's not correct. The dwell time is the amount of time the ignition coil primary has current running through it. So in a points ignition system, it is the amount of time the points are closed. There is only current sent to the spark plug when the points open. So if the dwell time is too short, the current in the primary coils of the ignition coil has not been able to build up far enough so there is not enough magnetic energy stored in the coil to give a good spark.
 
  • #5
I stand corrected.
 

Related to Understanding Dwell Time in Electronic Ignition Systems

What is dwell time in electronic ignition systems?

Dwell time refers to the length of time that the ignition coil is energized to create a spark in the spark plug. It is an important factor in the ignition system as it determines the amount of energy that is delivered to the spark plug and ultimately affects the engine's performance.

Why is dwell time important in electronic ignition systems?

Dwell time is important because it directly affects the amount of energy that is delivered to the spark plug. Too little dwell time can result in a weak or incomplete spark, leading to misfires and poor engine performance. On the other hand, too much dwell time can cause the coil to overheat and potentially damage the ignition system.

How is dwell time measured in electronic ignition systems?

Dwell time is typically measured in milliseconds (ms) and can be adjusted using a dwell meter, which is a specialized tool that measures the time the ignition coil is energized. In some modern vehicles, dwell time is automatically controlled by the engine control unit (ECU) based on various engine parameters.

What factors affect dwell time in electronic ignition systems?

Dwell time can be affected by various factors such as engine speed, engine load, and ignition timing. As the engine speed increases, the dwell time decreases to prevent the coil from overheating. Similarly, a higher engine load requires a longer dwell time to deliver enough energy to the spark plug. Ignition timing also plays a role in determining the optimal dwell time for the engine.

How can I troubleshoot issues with dwell time in electronic ignition systems?

If you are experiencing issues with your ignition system, it is important to first check the dwell time using a dwell meter. If the dwell time is outside of the recommended range for your vehicle, you may need to adjust the ignition timing or replace the ignition coil. It is also important to regularly maintain your ignition system to ensure proper dwell time and prevent any potential problems.

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