Kinda a noob question: Fuel filter??

Hey guys.

Is there an external, inline fuel filter on 4.0L XJ's? I am gearing up for a tune up and I would like to change what I can to help my XJ run a bit better. Where would this fuel filter be located if there is one?

What year?

I know for certain that RENIX (1987-1990) XJ's with 4.0 have a fuel filter where
you can get at it - it's on the left frame rail, forward of the gas tank, and about the size of a soda can.

I believe that OBD-I (1991-1995) XJ's have a similar filter in a similar place.

OBD-II (1996-up) XJ's have an in-tank filter that is not meant to be serviced, and functions as a pick-up for the pump. I'm not entirely too keen on a "lifetime" filter, but I've not owned one, so I can't be sure of a procedure for replacing the thing.

Posting your year and other basic info is a good habit to get into - as you can see, there are often several ways to answer a question. Something like this:

88XJ/4.0/BA-10/NP231/D30/D35 (3.07)

Is often useful - here's how you read it:

1988 XJ, 4.0L I6, with BA-10/5 five-speed manual transmission, New Process 231 transfer case, Dana 30 front axle, Dana 35 rear, with 3.07:1 axle gears.

Take that and modify it to apply to your vehicle. With the 4.0, if you've got an automatic you've got the Aisin-Warner AW4 (AW4 in place of BA-10,) all front axles from the factory were Dana 30, and the rear was either Dana 35 or Chrysler 8.25, or (rarely!) Dana 44. Dana axles are usually listed as "D" and the model number (D30, D35, D44, D60, or D80 - the latter are usually for swaps and upgrades, and you should tell us what the donor vehicle was, if you know,) and the ChryCo can be listed as "8.25", "M8.25", or "C8.25"

If you have a rear axle with C-clips (which were found, I believe, in later D35 and some C8.25,) you can append a "C" to the rear axle number - for instance, "D35C." Note that if you find a "D35C" on the axle housing is does NOT mean that you have C-clips - it means that the axle was shipped to ChryCo "unstuffed," and you'll have to pull the cover and look to see what you've got.

If you've got some sort of LSD, you'll want to note that in drivetrain comments as well - "D35 Trac-Lock" or "D44 Detroit" is sufficient.

I know it seems picky, but that one little line will honestly make it far easier for us to not answer your question with another question - like this started out...

5-90

My 96 has the filter on the frame rail. JIM.

Thanks. I'm not sure when they started doing the "in-tank, non-serviceable" filter, and it should be borne in mind that some owners added inline filters anyhow - when you take yours down (if you have,) are the hardlines that the rubber stubs clamp on to beaded? Or are they straight to the ends? If they're straight, it's definitely a "field modification," if they're beaded, it's probably an original setup.

I've got enough parts catalogues around here that I can probably find out - I just haven't bothered to yet. Probably another FAQ project for me to work on...

5-90

Mine's factory. It is the same as my 92. JIM.

When you change the fuel filter, it's a good idea to replace the rubber hose lines on both in and out sides. They're different sizes---5/16" and 3/8"---which you can get bulk at NAPA.

external on my 96 too, if there were any doubts.

I think its the 97 year model where they started using the in-tank filter exclusively. My 96 thankfully has a serviceable filter. Shame on Chrysler for removing it! I have plugged mine after only 1000 miles or so with bad gas. I wonder if there is any way for people to retrofit newer XJs with the older style serviceable filtration by removing the fuel pump, installing a older style screen pickup or even pump and adding the EFI inline filter.

I have a 97 with the in-tank filter. About a year ago I had a problem that I though was an clogged fuel filter. Turned out to be a bad sensor but before I figured the problem out I did all the research on changing out the in-tank filter and it look like a decent sized job.

ILLXJ said:

Mine's factory. It is the same as my 92. JIM.

Click to expand...

Cool, thanks. I'd have to check the OEMR books - I wonder if they went to the in-tank filter alongside the COP/Coil Rail ignition in 1999?

5-90

Geez, sorry 'bout that. My XJ is a 92.