Trouble starting once a day

Recently I have been having this problem where the car will not start in the morning unless I put the gas pedal all the way down and crank it a few times. After it has started once, it start up perfect for the rest of the day. It turns over when I turn the key but sometimes it does seem like it is struggling or quiet if that makes any sense. Once it does start I can smell the excess gas.

It has been very cold out lately and this problem only started after I was having some overheating trouble. The thermostat was replaced and the coolant drained. Could just be a coincidence that it only started after that. But it did only start happening since it has gotten colder out.

Anyone have an idea what this could be? It only happens in the morning when it is cold, once it has started once it is good for the rest of the day.

I do not think it is the battery because one day I sat there and cranked it time and time again. It turned over strong and sounded fine, just would not start. Then just before I gave up I put the gas pedal all the way down and sure enough it started up.