bought '89 camaro z28 to restore...has a few problems...every other time i try to start it nothing happens...nothing turns over...the car has full power...when its started it can run all day long...someone suggested trying to jump it....it starts right away when i do....why does it?...any suggestions? bad ground...starter..battery....and another problem---->my gas gauge seems to dance around alot...it might show how much gas i have for a second then goes and sits on E....under half a tank its impossible to know how much gas i have....whats up with that?....thanx for da help....