So my xj has 145k on the clock. It hasnt been run very much in the past 8 months, but the last week I have driven it about 3 times (not a daily driver).
I have only put 9k miles on it in almost 4 years. When I got it, I gave it a tune up - trans oil, engine oil, new rad and water pump, spark plugs, cap and rotor... am I leaving anything out... oh and pumpkin oil too.
I dont know when this would have begun to occur, but its starting to smell very rich and its not the rotten egg smell coming from the cat! I am not sure how to fix this and any help is appreciated.

 

How does the engine run at idle?

Pull the spark plugs and see if they, or any one, spark plug looks sooty. If all the plugs are sooty, there's a sensor issue, if only one is sooty the fuel injector for that cylinder may be bad.

How old are your Oxygen Sensors. Generally they're only good for around 130,000-150,000 miles.

 

Engine runs great.

Installed the plugs 9000 miles ago over a 4 year span. I havent checked them, but will tomorrow. If the injector is bad on one, shouldnt I change them all out? I heard or read on here that a 704 injector is the best. Do you have any knowledge for them?

As far as the o2 sensors, well I am not sure if they have or have not been replaced. On another forum, it said that if they are bad then the check engine light will come on and mine has not. With that said they are saying that I have an exhaust leak. Any knowledge on a good exh man relatively inexpensive, but might offer some performance? Rockauto.com has them for $139.

 

Before changing anything, see if you can get (rent/borrow/buy) a scanner that can read live data with the engine running and see if you are actually running rich. The Short Term Fuel Trim readouts will tell the story.

Where is it "starting to smell very rich", at the exhaust or in the engine bay?

 

Probably up near the front as when I get out of the jeep, thats where I smell it. I havent really noticed it anywhere else. I also notice it when I drive with the windows down.

 

I think you may have a fuel leak in the engine bay. You better check your fuel injectors for leaks. Your fuel injectors are notorious for leaking.

 

how do I check them, meaning do I start the engine and take an injector out one at a time or something?

 

Not possible.

What I am suggesting is that you may have an external fuel leak. Possibly a defective fuel injector that is leaking fuel in the engine bay. Start by turning the key to RUN to prime the fuel rail then inspect all the injectors for fuel leaking from the body of the injector, or past the o-ring at the rail.

If just priming the fuel rail gives no results, start the engine and check.

There could be fuel leaks elsewhere so you'll need to look around.

 

I don't mean to interrupt/ distract....Is the MAP still up in the firewall in 96? If so it has a brittle little tube to the TB, which carcked or clogged will cause some of what you describe. Very crucial that, (if it has one). (97 MAP, is on the TB).