The fuel pump could be in need of replacement also..They are in the tank of course..The tank does not have to be removed...The pumps have a sock like filter on the pickup tube that can get gunked up also..Especially on older XJ's that have sat...If its the fuel pump you will probably notice it the most when you mash the gas or go for passing gear which is a sign of not getting enough fuel...It will stumble , hesitate or backfire slightly even..
1990 XJ, 4x4, 2" Budget Boost 30x9.5-15
222,000 miles and counting..Update.. 250,000 and counting. Still no major repairs..
1989 XJ, 4x4, 2" BB, Wagoneer Limited (Woody)