The coil can be fine and throw a good spark when doing a coil check. If there is a good spark from the coil it does not mean that the igniter will trigger for a spark to be sent through the distributor to the proper plug.
Coil good and a bad igniter no spark to the plugs.
Igniter good and a bad coil also equals no spark to the plugs.
The igniter tells the coil to throw a spark when the rotor is pointing at the plug at the top of the compression stroke. Either one can be bad or very rarely both. these are separate parts in the same system.
Dave Neptune
