2008 4.3...this might be temp related.but when cold engine will crank and sputter like it wants to fire but usually wont. If I feather the accelerator when it does this I can get it to run as long as Im giving it gas.
After 10-15 minutes after it warms up I can hear the engine rev and its good to go.Have good fuel pressure and newer fuel pump and filter and recently ran god gas and heat and seafoam through it. Would this be one of the sensors? thanx

Also if I come back in 3 to 4 hours it will start fine but overnight not so much

 

I would change the ECT(engine coolant temp) sensor just on speculation, its not expensive

Not sure what engine you have?
4.3?
It would be a 2.3l or 4.0l, OR 3.0l in a 2008 Ranger