Private Pilot flying PA-28 aircraft reported engine malfunction in cruise flight.

Narrative

While traveling west bound over Island towards ZZZ; my home base; abeam ZZZ1; I experienced a brief loss of engine RPMs. I was at 2;750 ft. ZZZ1 Altimeter was 30.17. I then moved the throttle forward; there was no increase of RPM. I then called Approach; told them; I may have a problem; loss of engine power. The Controller asked if I wanted to declare an emergency; I said; 'not yet; I want to see if I am doing something incorrectly. Give me a minute and a half.' The aircraft was stable and the engine was performing. I then noticed the digital RPM screen was fading; and a red operation light went on. I again moved the throttle forward; no increase in RPM. But I was not losing power - I told Approach that I needed priority clearance to ZZZ; and could they alert them. They did and said I had clearance for any runway. A few minutes later he handed me off to ZZZ Tower. I told ZZZ's Tower I am heading for Runway XX- Runway XY was in use that day; but the winds were light. I was cleared to land on any runway. As I flew over the inner shoreline to line-up for final for Runway XX; the RPM's increased. I kept the throttle open to get me back to the airport quickly; and give me power. I landed on XX and there was no issue or incident.