2005 vette

wont start water damage change out BCM still having trouble car has started and run butnot when you need it

I’ll help you a bit. English does not seem to be your first language, not mine either.

(My) 2005 vette won’t start. (It had) water damage, change(d) out BCM (but) still having trouble. (My) car has started and run, but not when you need it.

“Water damage” pretty much tells you what you need to know.

What was the extent of the water damage? Was the car underwater?