The car hadn't been driven for a month. Since then, it has been weak and sluggish every time it starts cold. I just replaced the battery with a new one, but it's still the same. Is it a problem with the throttle valve, the water temperature sensor or the fuel pump?

 

It could be a dirty throttle body, a failing coolant temperature sensor, or a fuel pressure issue. Try cleaning the throttle body and checking fuel pressure on cold starts. Are there any check engine lights?

 

the check engine light isn't on,and there are not trouble codes