Just though it would be worth mentioning, I had some trouble with the fuel pump in my 87 this summer, it was running a little loud like that (I never had much gas in the tank, that might explain why) but at one point this summer, after running loud, it just wouldn't start back up again. I traced it down to a no fuel issue, which was funny because the pump was running, there was gas at the fuel filter, but nothing at the fuel rail and no leaks (external any ways). In the end I had to pull the gas tank becuse it turned out that there is a little rubber line (thanks again for telling me about it Old Man) on the Renix era XJs (luckily they use a Bousch pump that kicks ass, mine still runs great) that can rupture with age, this ruptured and severly cut down the flow to the point that it couldn't make it up to the fuel rail. I wouldn't really worry about it till it stops running, but it probably wouldn't hurt either to pull the sending unit and have a look at the pump hose. I had to drop my gas tank because the fastener for my gas tank was 18 years old and I needed to drop the tank just to get sending unit out. Anotherthing, just in case you want to look at the fuel pump, if you leave it out for awhile it will seize. This is because it is lubricated by the gasoline it pumps. I had a guy try to tell me the pump was shot and that it needed to be replaced. Honest to god just hit it "lightly" with a hammer a few times and it will start pumping again. You can bench test it with two leads and a battery.
