I tjhink your right ol Navy, I forgot to mention last week I ran about quart or so of PS diesel clean thru IP and engine, then replaced prefilter and main filter, didn't see any black specs. I remember trouble we had with JP-5 and micro orggies on the F8D,E crusaders fuel cells. were always replacing fuel p robes That was 40 yrs ago here in Beaufort and later on USS Oriskany. Bubba