How the mazda four cylinder engine fires its pistons.

The firing order is 1-3-4-2. When the outer two pistons are up, the inner two pistons are down and vice versa. The maiat ignition system deleivers spark to both pistons that are up, but only one of them will be at the top of a compression stroke.

 
Cylinder 1
 Cylinder 2
Cylinder 3
Cylinder 4

1. Top Dead Center
Cylinders 1 and 4 will spark

# 1 drives crank.
# 4 finishing exhaust stroke.
  Top of compression stroke Bottom of Firing Stroke Bottom of Intake STroke Top of Exhaust Stroke

2. TDC +180 degrees
Cylinders 2 and 3 will spark

# 3 drives crank.
# 2 finishing exhaust stroke.
         

3. TDC
Cylinders 1 and 4 will spark

# 4 drives crank.
# 1 finishing exhaust stroke.
         

3. TDC +180 degrees
Cylinders 2 and 3 will spark

# 2 drives crank.
# 3 finishing exhaust stroke.