OCV CIRCUIT MALFUNCTION

It starts great its a 1.8 L it does not want to rev you can flutter the gas it comes alive for a little bit but the only time is when the pedal is full floured it will rev all the way but half way and 3/4 it wont rev.
I cannot find a fuel filter and i changed the plugs , but it still has big dead spot in the rpm range.

Whats wrong is it the coolant temp sensor?