Hello, I recently purchased a 1988 Cherokee XJ Limited Edition and am currently working on completing the title transfer. My jeep just failed smog because the engine is running too rich. It has the 4.0L. 6 Cyl. engine installed. I am looking for some direction on a good place to start troubleshooting the rich-running condition and some information on tests to do to isolate the problem. Thank you in advance for the information.

 

Start by checking for/listening for vacuum leaks. Best place to start is the vacuum line that runs from the MAP sensor (mounted high on the firewall near the center of the engine compartment) to the throttle body. Any leak in that particular line will cause the engine to run rich.

 

Go to www.cruiser54.com and complete Tips 1 through 5.

Then, we can go from there.

 

Only California would ding a 30 year old Jeep for running 'too rich'. Sorry for my gripe... I just think it's BS for states to 'tax' the citizens over emissions. I didn't make the car!!! But it's far easier to come after me for $25 than hold auto manufacturers responsible.

Meanwhile diesel trucks....

I hope you get it fixed and pass. I have felt this pain several times in my past.

/rant out

 

I live in California, have my whole life. I personally love how much cleaner the air is now compared to when I was a kid. Also, my XJ passed its smog test so there is obviously something wrong with 88XJ87's that needs to be addressed. Blaming the state seems silly. There are plenty of other stupid things they do that I would love to rant about if this were a political forum. Gas tax, anybody?

88XJ87, I also live in OC and while I'm pretty busy right now, if you can't get this resolved, I could probably find an hour or two to go through your engine bay and see if we can figure out what's going on. Not that I'm a Jeep expert or anything but I know a couple things, mostly thanks to Cruiser.

 

It's not the smog testing that's cleaned up the air in cal. it's the cars makers the computers are better and helping keep the air clean the only thing is to keep all the sensors working right , but the problem with the state is they keep making to harder to pass a smog test . I have a 1997 chevy and the smog levels keep getting lower every time I have to smog it , the state does not want older cars on the streets . and they keep charging me more to register the car . On your xj not passing smog take a good look at your o2 sensor

 

Tips 1 through 5 first.......

 

X2. Breathing in Pasadena in 1962 was a real challenge.