What keeps the car from "flooding"?

I’d “guess” it doesn’t become flooded (end up up with cylinders awash with gasoline).

More backstory would be helpful. Repeated attempts at starting a reluctant Prius do tend tend to end up with no progress and a severely depleted hybrid battery.

 

You've got to go through the no start conditions kind of like a regular gas car for this portion coils plugs ignition stuff air is actually getting through the filter in the piping to the intake and so on That's just the way it has to be initially so what it seems like anyway.

 

I'm pretty confident modern EFI injects fuel only after the engine has started spinning.

 

If I was designing a system like that the injectors and spark would be enabled and disabled at almost the same time. There would be a slight offset for when the ICE is shutting down, the spark isn't disabled after a cylinder has been filled with fuel. When starting the ICE it could be simultaneous, since firing the plug in a cylinder which hasn't been fueled is harmless. It wouldn't be strictly linked to the motor spinning though, since I believer there are times where the Prius spins the ICE without turning it on when "B" is engaged.

 

I haven't studied it in any detail for a Prius but plenty of other cars use the convention of timing ignition from the crank and timing the fuel injectors from the cam sensor.

In theory you could reference the cam sensor for both, but if you use the crank sensor for spark you get twice as much time resolution and therefore better accuracy.

 

Also, the crank sensor (on a Prius anyway) has a lot of teeth, and the cam sensor has a few teeth, so the crank resolution is way more than twice as fine.