Also check the radio interference suppression relay. It's the one mounted right next to the coolant bottle, on the right strut tower. The name is misleading---it supplies voltage to the injectors. They often fail intermittently, causing symptoms similar to what you describe. The failure is due to bad solder joints inside the unit---the jolt of slamming the hood could move it enough to let current through for a while. I've had three of these relays go bad, but never had a problem with the ignition amplifier. Next time it won't start, see if it has spark. If yes--suppressor relay. If no---amplifier or other ignition component.