I’m making potatoe salad and I used a little too much vinegar is there anyway to cut that taste!

I'd add mayo as well, even if the original plan was no mayo. Or is there a sweeter juice that would match the other flavors, like orange juice - might be good if it's an olive-y, caper-y type of potato salad. A splash might help - you could try it on a small portion to see. That or add more potatoes, if I really wanted to keep to the original recipe.

i would dice and boil up some more potatoes and mix them in. it will dilute the taste.

I forgot to add... you could also use some sweet pickle relish including a little of the juice, to offset the vinegar.

A little mayo would even out the vinegar "bite." You might want to mix a pinch of sugar (not too much!) or a drizzle of honey into the mayo - but do it with a light touch.