CM 870 Smoking white

[Ken Worth]

Hello guys my cm 870 started smoking white smoke and what feels like sputtering when reving up. But If I take off and start driving the smoke stops and truck is normal/ no power loss , or if I raise the ideal up to 1100-1200 and hold it there it will smoke for a little and then clear out to normal no smoke no sputtering nothing.

Any ideas what could be causing this? Thanks guys

So far I changed fuel filters.