Q: Car stutters on initial startup when cold 2001 Toyota Camry

Hello - a "hard start when cold, or left overnight" is usually a fuel mixture problem during cold start. The coolant and air temperature sensors cause problems when they do not accurately measure coolant and air temperatures, report bad temperature information to engine management, and cause either a "too rich" or a "too lean" mixture condition. A failing fuel pressure regulator or fuel pressure check valve can cause low fuel pressure issues, but that is usually resolved in less than a minute or two after engine startup. Re-starting during the day for all of these conditions will tend to be more normal. I recommend a hard starting inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, narrow this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.