The firing order of a Ford engine determines how the coil sends electrical power to the spark plugs to detonate the fuel in the cylinder. If a person attaches the plug wires in the wrong order, the engine runs poorly or does not run.
Gasoline engines use spark plugs to cause an explosion of fuel within the cylinder. In a properly timed engine, this explosion occurs at the proper moment to send the piston to the bottom of the cylinder and provide power to the drive shaft. If the plug wires are out of sequence, the explosion occurs at the wrong time. The improper timing of the explosion sometimes pushes the cylinder the wrong direction or interferes with the turning of the crank. As a result, the engine stutters or backfires, if it runs at all.
In-line Ford engines, along with those of most other manufacturers, begin the numbering of cylinders at the front and proceed in numerical order toward the back. In the V-engine design, Ford follows a similar design with the number one cylinder at the front left of the engine. In the V-6 configuration, cylinder 4 is at the front right of the engine and in a V-8, cylinder number 5 is in that location. Other manufacturers sometimes use an alternating pattern in the V-engines.