Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. What Does Ignition Timing Mean?

What Does Ignition Timing Mean?

Spark Plug Arc

Timing – it has a couple of different meanings when applied to your car’s engine. One of the most critical is ignition timing (not to be confused with engine timing). Ignition timing refers to when spark is created during the engine’s cycle. It needs to be just right or you end up losing power, increasing fuel consumption and producing more emissions in your exhaust.

What’s timing all about?

Your engine runs on a controlled series of explosions. Spark plugs create their spark to ignite fuel vapors. This creates combustion. The explosion then pushes down the piston, which turns the camshaft. However, the plug can’t fire at just any time. It needs to be timed correctly with the engine’s motion.

There are four cycles in an automotive engine (thus the name four stroke). These are:

  • Intake
  • Compression
  • Combustion
  • Exhaust

The spark plug must fire at the right point in these cycles to maximize the power created by combustion. The system should fire before the piston hits top dead center (TDC). The increase in pressure from combustion pushes the piston back down (after reaching TDC), and turns the camshaft. The reason that the plugs need to fire before the piston hits TDC is that if it didn’t happen then, by the time combustion actually occurred, the piston would be so far into its downward motion that the force of the combustion would be largely wasted.

Remember: while gas is highly combustible, it doesn’t burn instantaneously. There is always a delay. By firing before the piston hits TDC, your engine is able to account for this delay and maximize the amount of power each time.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....


Related questions

Q: Can I continue to drive my car until I get the ignition coil fixed?

Hello Since the ignition coil is the component responsible for generating the engine spark, any problems with it can quickly lead to engine performance issues. Because of this fact, it's not really a good idea to drive the vehicle any...

Q: Q: Car dying when put into gear

Your concern can be as simple as a broken/dry rotten hose that may be allowing too much air into the engine. The ignition system must be well-tuned and the alternator must be capable of charging the battery during vehicle operation....

Q: Why am I getting quotes for spark plug replacement for a 2008 Toyota Avalon of 495?

Spark plugs on your model do require relatively more labor time to replace, compared to other vehicles. That is why the quote you are getting seems high for a part that is so simple. However, your general supposition that the...