Without someone making some very important voltage measurements, (specifically the voltage available at the ignition switch side of the ignition coil primary winding during cranking), it's going to be impossible to give you any meaningful advice. One loose or dirty connection resulting in a voltage loss to the coil, or a high resistance contact inside the ignition switch can cause the symptoms you're getting. Even a too-small battery cable can reduce the voltage available to the starter and cause voltage drop at the coil. Making broad generalizations about what's wrong simply won't work. Either go to the effort to do some diagnosis yourself, or pay somebody who knows what he's doing to do it for you. We're not magicians here.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!