Stumped and Frustrated with a Holley 670 Hesitation

Is this from a standing start,, or from speed..??

Initial timing??

The secondary springs are color coded, and there's about 7 diff strengths,, which do you have..?? By the sound of it, you need a stiffer spring.. or you may need to change accel pump cams to a longer stroke..

White - Lightest
Yellow (Short Spring)
Yellow
Purple
Plain (Steel grey)
Brown
Black - Heaviest

hope it helps.