Temp Gauge and Fuel Gauging "Surging" or Bouncing

Recently my temperature gauge and fuel gauge have developed a weird "surge" or bouncing. While driving the car the ammeter holds steady close to center on the gauge with no bouncing. But the temp gauge and fuel gauge are pretty constantly bouncing. This is new phenomenon for the car. When I redid the dash I installed a new IVR. I also added new grounds on the back. I don't seem to have any electrical issues in the dash otherwise. Dash lights work; switches work. Any thoughts or advice would be appreciated.