Started 2 days ago after sitting for 2 weeks, started right up. tried starting after a cold night maybe got down to 38 temp. replaced coolant resevior added anti-freeze will crank, but wont turn over

hmm try to check all bolt and pipes

What engine does it have ? 3.6 or 3.8 l Does it have flex fuel ? How long do you work 8 hrs. Sould be cold after that , unless it's hot where you live . Hooking up a scan tool an viewing live data from the coolant temp sensor , could be lying to the PCM/ECM ,does the IAT intake air temp sensor show close to what the coolant temp sensor shows ? The PCM/ECM goes by what the coolant temp sensor says for fuel control ,when it says the engine is cold when it is really hot the computer will supply too much fuel causing a hard or not start problem . Try holding the gas pedal all the way to the floor after work an see if it starts then , holding the pedal to the floor puts the fuel system into clear flood mode , only gives half the fuel . Engine flooded .
Clear Flood Mode
If the engine floods, clear the engine by pressing the accelerator pedal down to the floor and then crank the engine. When the throttle position (TP) sensor is at wide open throttle (WOT), the powertrain control module (PCM) reduces the fuel injector pulse width in order to increase the air to fuel ratio. The PCM holds this injector rate as long as the throttle stays wide open and the engine speed is below a predetermined RPM. If the throttle is not held wide open, the PCM returns to the starting mode.

Hooking up a scan tool an viewing live data is still best way to diagnose , not guessing an cleaning parts .

The two most common causes are: fuel pressure leakdown after sitting for a while and an engine coolant temp sensor. The culprit is a leaking check valve in the fuel pump. To test, turn the key to ON for 2-secs, then OFF. Repeat 3 times. The try starting. If it fires right up, have the shop do an overnight leakdown test. If the fuel system loses more the 5-8-psi overnight, then the pump must be replaced. Test 2 is to check the engine coolant temp sensor. A sensor that's off usually reports a warmer engine than actual so the computer provides too lean a startup mixture. Try depressing the gas pedal halfway. If it starts right up. have the coolant sensor tested.

The thing to do is have the vehicle hooked up to diagnostic scan tool . Viewing engine sensor data ,see whats off . The computer may think the vehicle is warmer then it is an giving it less fuel . Checking coolant temp sensor data , IAT - intake air temp sensor . 048 Engine Hard to Start or No Start Scan Data for Starting Problems

What is the fuel pressure when this happens? You may have a defective fuel pump inside the fuel tank, it is bleeding down and this causes a loss of pressure and hard starting cold.

Sure the engine coolant will be warmer than the outside temperture and if the car has been sitting a long time in cold weather and the outside temperture warms up it could be the other way around. The coolant temperture sensers aren't real accurate as they are a relaitive senser beween hot and cold and the numbers reported don't have to be real just the change from hot to cold and the reching of the coolant to the operating temperture. Noe it the senser doesn't read the opertating temperture coprrectly you'll have all kinds of problems. The therostaste will try to set the temperture of the water to it's set temperture and can open or close completly to get 195 degrees F. Many times if it's too cold then the stat is bad and needs to be replaced This shows up in alot of cars first thing after winter and the first onset of cold weather when the daily tempertures vary the most from day to night.

temp coolant sensor maybe.

Sounds like you could be low on coolant, even more so because the air starts to cool down, check coolant level with engine cold, never open a radiator when hot.

you have water in the fuel line