I inherited my grandfather's 1981 International 986 and it has been a great tractor, but last Fall I was pulling a plow behind it getting ready to plant some ryegrass and the tractor started sputtering with RPMs going up and down for about 20 seconds and then it died. I was able to crank it back up with ether, but the RPMs were going up and down, and after about 20 seconds it quit again. Again, cranked with ether, tractor ran rough, was able to give it a touch of ether to keep it running, limped it out of the middle of the field and parked it under a tree and left it there until this afternoon. Today the tractor was sluggish to start but once it fired I was able to drive it around smoothly for about 1,000 feet but then I could hear it start to sputter and slowly it died again, same behavior as before. Pretty sure it's a fuel issue but it's got fresh fuel in the tank and two fresh fuel filters. I cracked the rubber fuel hose between the filters and the pump and pushed the primer in and out and fuel was flowing out good of the hose and the primer had good pressure. Was wondering if anyone had any ideas on what is causing this issue? See photos for my fuel pump, filter, and lines setup.