how much would it cost to re wire the engine of a 2007 subaru impreza on 2007 Subaru Impreza

it had previous fresh water flood salvage title. the engine turns, but does not turn on, what can i do to fix the problem?

What was the extent of the damage? Was ECU under water at all?
yes the ECU was under water
I would start with replacing that first. Unless visibly damaged, wiring itself doesnt suffer nearly as much from water damage as ECU does.
thank you i will, but would i be able to start the engine withouth it, maybe not drive, but start the engine to know its still alive