Car stalls and misfires at normal temperature. Then the temperature gauge goes down and it starts to missfire a lot and stalls

Hello, I'm Danny
Just a quick question first.Due to this issue has it set the check engine light? If so that means trouble codes are stored in the vehicles computer.This helps aid us in the diagnosis.If you don't have any access to a code reader your local auto parts stores have a tool loaner program and can rent you one.Here is a tutorial showing what is involved.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Once you can provide us with the trouble codes we would be happy to address the malfunctions.Hope this helps and thanks for using 2CarPros.
Danny-