You can only start in the throttle only position because the engine is flooding. So that is what it is doing. The next step is trying to figure out why it is flooding, and that can happen for a number of reasons as well.
1. If fuel pressure is leaking down that means the injectors are leaking, dripping fuel into the engine when it is off.
2. If the thermostat is bad and the engine is always cold, that will cause it to flood on a hot restart
3. If the temperature sensor is bad, and the engines computer thinks it is always cold when it is really hot, that would cause it to inject to much fuel and flood the engine
4. If the throttle positioning sensor is out of spec, or out of adjustment, that would also cause the engine to inject to much fuel.
So those 4 areas would need some deeper investigation. It is definitely flooding, the next step would be to find out why it is flooding. Does that make sense?