ISO: Texas Caviar - Can someone help me fix this recipe?

I tried this recipe someone gave to me and it just seems off, I made it twice and threw away both batches. The dressing is off somehow, it called for 1/2 cup of cider vinegar, 3/4 cup olive oil, 1/2 cup of sugar, and 1/2 tsp of salt and pepper. The first batch I made was way too sweet so I put less sugar in the next batch, but when I made the next batch the vinegar overpowered the dressing. I think the person who gave the recipe to me does the dressing to taste cause the recipe is hard to follow so I know its not me. Can someone help me fix this recipe?