This means that the spark plugs fire in that order, starting with cylinder #1.
To determine the cylinder numbering, you can use the following guidelines:
* Front of engine: Cylinder #1 is typically the front-most cylinder on the passenger side of the engine.
* Driver's side: Cylinders 2, 3, 4, 5, 6, and 7 are on the driver's side.
* Rear of engine: Cylinder #8 is the rear-most cylinder on the driver's side.
Keep in mind that the firing order can vary slightly depending on the specific application of the engine. It's always a good idea to double-check the firing order in your vehicle's owner's manual or a reliable repair manual for your specific model year and engine code.
