My engine will not start up and run why?

When I start up my car, my Coolant gauge will go to the correct temperature for about two minutes, than it will drop down to completely cold. Once cold, my engine idles in the 2000 region.

Not only that, after I drive my car and than start it up again like 10 minutes later, I have problems starting it, it cranks but won't fire and usually takes a good 1-2 minutes to get it to fire. (I believe it's because the engine is flooded after driving at this point)

Any idea what could be wrong here? I was told MAS could be bad, but I don't think these saturns have one. So my only conclusion is the coolant temp sensor.

I appreciate your help! :)