2006 Mazda 3 Starting Problem

I have a 2006 Mazda 3, standard transmission. About once a month, randomly, my car will not start. Usually within a few hours or a few days, the car will start again. I’ve had the battery checked out and its okay. I’ve had the clutch switch replaced. Every time I take it to a mechanic the car starts again so they can’t seem to diagnose the problem. Any ideas?

“Can’t start” isn’t enough information:

  1. Nothing whatsoever happens – Probably an ignition switch problem or maybe a safety interlock
  2. Single distinct click from under the hood then nothing happens – Battery, cables, connections, dead starter.
  3. Starter grinds unenthusiastically. Engine tries to turn over. Maybe makes it a few times – Battery, cables, connections, dying starter.
  4. Starter turns engine over but it doesn’t fire – Probably the fuel pump or ignition system.
  5. Starter turns over, engine fires sometimes but doesn’t stay started – Most likely ignition system, but could be fuel pump, or maybe something else.

Nothing whatsoever happens. My dashboard lights come on and my headlights and radio work, but no sounds from the car.