Does over watering a citrus tree (gfruit) bear smaller fruit?

new home owner with 20+ yr old gfruit tree on property. house was empty 9 months prior to my purchase last december. ground was super dry, dead lawn, but tree had full size fruit. after purchase i watered plenty to bring back lawn. when gfruit tree flowered fruit bear is now under size, size like naval oranges, still green. tree hit with leaf miners and pruning over summer. i fertilized once in spring, and plenty water. any sites, advise, or answers? TIA