It appears that I solved the issue...just by chance. I decided to hook up my auxiliary tank I use when doing a purge. I filled it with diesel and hooked up the supply and return hoses that are attached to my auxiliary tank and the issue went away. Apparently the supply hose on the car was pulling air. I pulled it off the car and inspected it closely. Sure enough, it was full of hairline cracks. I installed a brand new supply hose and now she’s nice and quiet.