I just put a 4.0 in a CJ7 at 500 miles ago and the fuel pump pooped out today. It was an Airtex universal inline and I mounted up behind the DS wheel well and then put a sheetmetal cover over it so the mud would not get up there. I am wondering are the Airtex pumps that bad or is it possibly overheating in the confined space? I figured the fuel flowing through it would cool it off. I works for a little while now but then go TU and you have to let it sit for awhile before it will work again. Not working it is fairly quiet, working it is pretty loud now.