With the xj running, If I pop the hood i can smell a sulfur/rotten egg smell coming from the left side of the engine compartment. What do you think this means?

 

Change brand of gasoline you are using.

 

That sort of smell could be an indication of very old fuel! I had the very same smell in one of my cars that had been in storage for two years. Wouldn't start, all I had to do was drain and rep,ace the fuel and everything was fine.
Jeroen

 

Could be your catalytic converter.

 

Check your cat converter. My firebird had a gutted cat and it smelled like rotten eggs.

 

def the the cat. ive never had anything sit that long to confirm that could even happen. i would change the cat out. how many miles are on the cat???

 

do you have a cel?
A vacuum leak can make the computer see it running lean, then richen it up then clog the cat.
check it all out so you don't put a cat in then need another one in a few months.

 

X2. excellent point Scott. I didnt even think of that.haha. yeah def check what Scott said.

 

Your battery is sulfated. I'd bet money on it.

 

I didn't even think of that. But yes a battery can smell like that to.

 

The smell is coming from the left side? You mean the drivers side...correct? Because all my batteries are on the PASSENGER side...rotten egg is cat...