04" S80 T6 won't start at 20 degrees F or lower
 

My 2004 Volvo S80 T6 will not start when the temp drops below 20 degrees F. The engine turns over fine, but will not start. Usually a small amount of starting fluid sprayed in the air cleaner box will get the car started. In the past 20K this car has had a new throttle body, new mass air sensor, new fuel pressure regulator, new fuel filter, new crank trigger and new spark plugs installed. Any ideas to fix this latest problem would be greatly appreciated.

Thanks

Could be a bad coolant temp sensor. Does it have any codes?