My car struggles to start when cold and I sometimes have to tighten or lossen the camshaft sensor for it to start and even when it does start, it the doesn't want to idle when its still cold , it needs me to drive around so it can be hot so that it can idle. please i have went to a lot of machanics and they changed everything(throttle body, fuel pump, knock sensor) without a difference and i only notice a diffrence when i losen of unlossen the camshatft sensor. please help urgrntly