Lately I've been feeling like my XJ is losing power. Tonight I came to a complete stop at a stop sign, and the XJ completely shut off. I tried to crank it and it fired right up. Weird. So I make a turn and it feels like power is slipping again. It's almost like I'm out of gas but I know I'm not. Any suggestions?

 

Recent decrease in fuel mileage?

Take it for another drive, then look underneath and see if the cat is glowing red. Or crawl under and hit the cat with your palm listening for a rattle.

Thats the first thing i would check. Second would be a new fuel filter.

 

Fuel pump is my vote (oops fixed it. i said filter by mistake). My gf's grand am did the exact same thing you (OP) described. I couldn't figure it out and it eventually just wouldn't start. A mechanic came to the parking lot, put his ear next to the opened gas filler tube while the other turned the key to "on" and he immediately knew it was the fuel pump.

$594 later and it runs like it has a v-8.

 

If it's not the cat or fuel filter, my money would be on the Fuel Pump being bad with those symptoms.

 

Just replaced the fuel pump last October. Do these things go bad that quickly? Or maybe my mileage has gone down from 15 since the addition of my mud tires. I guess I'll try a few of these suggestions. Thanks.

 

Check your fuel pressure. could just be a broken wire to the pump as well.

 

Just how much bigger than stock are your "New Mud Tires"??? If they are bigger than stock and you are still running the stock axle gears, losing power is a normal thing.

 

clean out your throttle body and stuff and check for carbon build up, this was happening to me recently