1993 Honda Accord car won't start periodically unless until

The engine won't turn over. It wants to but doesn't seem to get that spark to fire the engine. Once I put jumper cables on it it turns right over and runs great. I've had the battery, plugs, alternator, and battery cables checked and been told they're ok.
Someone suggested it could be the cam sensor.
The check engine light does not come on at all.
It's like the jump is sending additional power to the engine and overriding what ever is causing it not to start.