01 Launch overheated - impeller is fine??

I was putting home after a party on Weds night, gave her some gas, started to accelerate and the engine dropped back to idle by itself. Noticed the temp gauge was around 220!! opened the cover and it was very hot.

I was allready 1/2 way home so I just idled in to the slip, but by this time the engine was smoking a little bit and the manifolds were too hot to touch.

Checked the impeller the next day, it is fine except that there was hardly any water in the pump. The filter off of the intake line had some crap in it, but not too bad.

Has anyone ever had anything get past the filter and plug the lines somewhere?? the line between the filter and the water pump hardly had any water in it. any tips??

Hope that the engine will be okay once we figure out wtf happened.......