Q.can certain nutrients increase my lilac’s fragrance?
I am getting 4-5 blooms the first of April in Oregon, which possess very minimal fragrance. Is there anything I can do to enhance that fragrance? What fertilizers would you recommend? I know ammonium sulfate is supposed to enhance blueberry size/flavor. Is there anything like that for lilacs?

Nutrients can't change the fragrance that your Lilac emits, but certainly a healthy plant will produce more flowers and will not only look showy but more flowers will likely produce more fragrance then just a few flowers.
Here is a link with more information on Lilac care.
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-plant-fertilizer.htm