3.5 2011 impala engine stumble tach drop

2011 impala 3.5 flex. When you first take off at the end of the day whith
moderate acceleration the engine will balk and loss of power. If you let off the
gas it’ll smooth out, but if you push it and try to go it will stutter and the tach
will drop to 0. It will spit and sputter but will go until you shut the engine off for
15-20 seconds. On restart tach is fine and engine runs fine. Does not do this
when it’s warmed up and not affected by temp. Rest of the time runs beautiful