Inline 4 Firing Order [With Diagram]

The term “straight-four engine” refers to any internal combustion vehicle that has its four pistons aligned in a horizontal line. How each cylinder’s spark plug is ignited is referred to as an engine’s “cross-plane” inline-4 firing order. When a gas or petrol engine has spark ignition, the firing order is determined by the sequence in which the spark plugs are activated.

The order in which gasoline is pumped into each cylinder determines the firing order of a diesel engine, and this order refers to the firing order. Because the valves do not open and shut with each stroke, four-stroke engines need careful timing of the opening and closing of the valves about the firing sequence.

Inline 4 Firing Order

  • Firing Order: 1-3-4-2

Explanation of Inline 4 Firing Order

To ensure that the engine operates without any problems and that there is a successful transfer of power from the motor to the rotor, this process has to be performed to the letter. How to check the spark plug firing order? To get the combustion process going, the spark plug for the first cylinder is the one that gets ignited initially.

The next component in the arrangement is the third cylinder. The starting motor of cylinder number four will then be the one to ignite, and ultimately, cylinder number two will become operational after that. If you rotate the distributor cap in a clockwise manner, you will see a pattern that corresponds to the firing sequence of 1-3-4-2. You need to make sure that you mark or note the position of cylinder number one since it will act as a starting point for you to discover the following cylinders in the chain.

The chain starts with cylinder number one, which may be located at the very beginning. The starting point will dictate the remainder of the sequence; the firing order for a 4-cylinder inline engine will be 1-3-4-2. If you position it in the wrong way, the whole process will be disrupted, and the engine won’t be able to start as a result.

Firing Order Applies to:

  1. Mercedes-Benz SL43.
  2. Honda Civic Si.
  3. Subaru BRZ.
  4. Toyota Supra 2.0.
  5. Mercedes-Benz A45 S.

Torque Specifications

Fastener TypeTorque Spec
7/16 in. Outer Main Cap Bolt70 ft.-lbs.
7/16 in. Inner Main Cap Bolt75 ft.-lbs.
3/8 in. Outer Main Cap Bolt35 ft.-lbs.
11/32 in. Connecting Rod Bolt38-44 ft.-lbs.
3/8 in. Connecting Rod Bolt40-45 ft,-lbs.

Firing Order For Similar Vehicles:

  • Honda Accord 1-3-4-2
  • Chevrolet Malibu 1-3-4-2
  • Subaru Impreza 1-3-4-2
  • Hyundai Elantra 1-3-4-2
  • Subaru WRX STI 305-HP 1-3-4-2
  • Honda Civic Type R 1-3-4-2
  • Ford Mustang EcoBoost 1-3-4-2

What is the firing order of a 4-cylinder?


How many firing orders are possible for a 4-cylinder inline engine? Other potential firing orders for 4-cylinder engines are 1-3-2-4, 1-4-3-2, and 1-2-4-3. However, the most common firing order for 4-cylinder engines is 1-3-4-2.   In most engines, the cylinders are designated starting at the front of the engine, where the auxiliary drives are located, and working their way backward.

Are 4-cylinder and inline-4 the same?

A straight-four engine, also known as an inline-four engine, seems to be a piston engine with four cylinders that are organized such that the cylinders are lined up in a row along a single crankshaft. The firing order in a 4-cylinder inline engine is 1-3-4-2, which is the most popular.

How is the design affected by the sequence?

The crankshaft design is highly impacted by the firing sequence, which has a significant impact on the vibration, loudness, and constancy of power production from the engine. The crankpins of an engine with four cylinders are spaced ninety degrees apart from one another. Therefore, the firing order of an inline 4-cylinder engine typically follows either the 1-3-4-2 or the 1-2-4-3 pattern.

Jake Mayock