VIDEO: Checking For Spark Inside And Outside The Engine

Checking to see if there is spark by firing the ignition coil and spark plug outside of the cylinder is not a valid test. It shows that the coil and spark plug is firing, but this is at 16 psi of atmosphere and not 1,000 psi in the combustion chamber. In this video we discuss what it takes to fire a spark plug under pressure. This video is sponsored by Autolite.