1990 Chevy Lumina Sputters while cold

When I start my car when cold it runs rough like it's missing and sputtering. If I let the engine really warm up a good 20-30 min the rough idle and sputtering while accelerating goes away and the car sounds pretty good. Pretty much Only runs rough when cold. Usually. Replaced plugs and wires had the ignition module and fuel filter done a few months ago.