1990 Buick LeSabre cold starting problem

I have a 1990 Buick LeSabre, v/6 3800, runs great flawless, til the outside temp's get below 30, then it doesn't want to start. Act's like it's outta time,back coughs, etc. But soon as it gets above 30 it will start and run great. Battery is good, new plugs, new starter, etc. Anyone out there with same problem, would really appreciate your help.

Scan it and check temp sensor readings make sure they match the cold outside temp, when cold of course, also fuel not blended for winter can contribute to this, poor condition plugs another possibility.