I agree with checking the low-oil sensor. I had a helper pour oil in a tank and the force of the oil bent the sheet metal bracket. But my first thought is that the valve (Maxton) is stalling on a relevel when the oil is warm (especially in the afternoon). Run the UL adjuster all of the way in and verify the car levels up between 5-9 fpm. The regulator (modulator called by some) is a mechanical way for the valve to ensure the speed is constant no matter what the viscosity is. The UL port can be affected by warm/low viscosity oil. Use the UL adjuster for fine tuning, and not to obtain the speed in its entirety.
