I have a 2000 5.9 cummins and I was driving home from work about 10 min away from my house and I noticed my fuel pressure fluctuating up to around 15 or 16 psiand groping back down to 12 or 11 it usually sits at 12 psi at idle and around 9 at wot so when I got home and got out of the truck and right away I could smell diesel fuel so I got under and there’s fuel dripping down the side of the tank from the top cap area not enough to drip on the ground just enough to get get the side of the tank wet I checked the lines every things connected it looks like it coming from like a seal under the cap keep in mind I only have just under quarter tank 70 miles left on the overhead display what could it be