Wash potatoes. Place in Instant Pot on the trivet or in steamer basket. Add 1 cup water to Instant Pot, close lid and set to sealing. Pressure cook on Manual for 5 minutes. (8 minutes if you live at high elevation) When time is done, allow to Natural Release pressure. Remove potatoes, place on plate and allow to cool to room temperature.
Place eggs in a pan of water and bring to a boil. Boil eggs for 10 minutes. Remove from heat and drain hot water. Cover eggs with cold watwer and allow to cool. Remove shells.
When potatoes are cool, peel and cut into 1/2 inch pieces. Cut eggs into 1/2 inch pieces. Dice onion and celery very small.
Stir miracle whip and sugar together till sugar is dissolved. Add vinegar and mustard. Stir well.
Place potatoes, eggs, celery, onions in a large bowl. Add dressing and stir together gently. Chill thoroughly. Store in an airtight container in fridge, up to 3 days.
Notes
I like to add 1/2 - 1 cup diced pickles, if I have some on hand. Sweet pickles or dill pickles are both good! They add a pop of flavor and some more crunch. If you don't have an Instant Pot, you can just boil the potatoes. It will take about 20-25 minutes to boil whole potatoes on the stovetop.Potato salad does not freeze well. Best if eaten within 3 days.