Fuel Filter Replacement?

I'm going to replace my fuel filter, but as I was look at my Haynes manual it said I need to depressurize the fuel system which involves removing a fuel line. When I looked at how to do that in Haynes it said I'd have to replace o-rings.

I've never replaced a fuel filter before.

I have a 2001 XJ 4.0L.

I appreciate the help.

The fuel filter on your 2001 4.0 engine is part of the fuel pump "assembly", located inside the gas tank. The "assembly" consists of fuel pump, regulator, and filter.

The fuel filter for 1997-2001 engines is not generally replaced as a preventive maintenance item. Rather, the entire assembly is usually replaced when symptomatic and when fuel pressure testing points to it.

Well that kind of sucks. I guess I'll have to go find some pressure gauges. Is replacing the fuel pump assembly something that can be done easily?

Yup, thats not something I would just do for the hell of it. But I have had to do it. Use a floor jack to lower the tank onto 4x4's and slide it out. Obviously disconnecting stuff as you go.

And the worthless Haynes/Chilton manuals strike again.

In case you do decide to change it eventually... OE p/n 4798301

http://www.jeep4x4center.com/product-information.asp?number=4798301

From what I can tell the fuel filter on the 97+ tank is not IN the tank per se - it is the small metal canister looking thing clipped onto the top of the pump assembly. You still need to drop the tank to get to the @#%@#%ing thing (or bore an access hole through the floor right above it, if you so choose) but you don't have to pull the fuel pump, which is quite nice. Unclip the stainless steel clip holding the filter onto the top, remove the quickdisconnect line from the side, then use a pair of flat blade screwdrivers to pop the module out vertically. Don't be too bashful with the screwdrivers, it took a little bit of twisting them to lever the one out on my spare 97+ pump assembly I broke down and reassembled a few days ago.

EDIT: JrTxJ's post verifies this, it's not in the tank, just on top of it.

I *think* the check valve may be built into the same module, but I am unsure.

If you are a lazy guy like me, buy two new J-bolts (part number J3240023) on funjeepsparts.com for 2 dollars apiece, 2 fender washers to fit them, and 2 nylock nuts at Home Depot. Might want to get something else you need at funjeepsparts at the same time unless you like paying 8 bucks shipping on 4 bucks of parts - I don't work for them, they just have the best price I can find, they beat OEM MSRP by 50% ($4.change each) and teamcherokee by 90% ($20 for 2) :shocked:

There is a sock type filter on the pick-up as well.
I've usually had good luck with morris4x4's diagrams, but there seems to be a little discrepancy with pumps and years.

Yea I need to check the pressures. I've just been lazy and was hoping I could just replace the fuel filter. My MPG is pretty sorry at around 14MPG on the highway and maybe 13 around the city.

I've replaced everything else I could think of related to improving mileage.

joe_peters said:

And the worthless Haynes/Chilton manuals strike again.

Click to expand...

Yea it's pretty much a piece of junk. Hasn't really helped me with anything yet.

LazersGoPEWPEW said:

Yea I need to check the pressures. I've just been lazy and was hoping I could just replace the fuel filter. My MPG is pretty sorry at around 14MPG on the highway and maybe 13 around the city.

I've replaced everything else I could think of related to improving mileage.



Yea it's pretty much a piece of junk. Hasn't really helped me with anything yet.

Click to expand...

RANT: It frosts my shorts that those slovenly SOBs at Haynes and Chilton can keep selling the same BS manuals--XJs out of production for 8 years and the scumbags haven't updated or fixed a damn thing in their crappy manuals. Its not like something is going to change in next year's model!

Rant over.

Has anyone checked pressures on an 01 XJ?

Yeah, you just need a fuel pressure gauge with a fitting for the scrader(sp?) valve on your injector rail. They can be had at most, if not all auto parts stores for 30- 40 bucks. Or do like I did and pay in excess of 150 bucks for one off of a tool truck with a fancy name on it that does the same thing.:dunce:

What psi should I look for and what will that tell me?

Should be a good 49 psi and fairly steady. It will tell you that the filter is probably not plugged, that the pump is providing the correct pressure to the rest of the fuel system, that the pressure regulator hasn't failed allowing the pressure to raise to unsafe limits. When you shut off the engine you can observe the amount of time before the pressure starts to fall off and that will tell you the approximate condition of the check valve.

Alright well I'll be heading to the base shop tomorrow to go throw some fuel gauges on.

Well stopped by the auto hobby shop on base tonight and the fuel pressure was at 50psi steady. I'm not sure where to go from here. I'm kind of at a loss now. I have no idea what is causing my mpg deterioration or my random misfires.

Below are 3 links to a series in JP Magazine on XJ fuel mileage. One item of particular interest is the impact a failing accessory--p/s pump--had on mileage.

MPG:


http://www.jpmagazine.com/projectbuild/154_0808_building_a_fuel_efficient_jeep/index.html


http://www.jpmagazine.com/projectbuild/154_0810_building_a_fuel_efficient_jeep_part_2/index.html


http://www.jpmagazine.com/projectbu...cherokee_xj_project_mileage_master/index.html


Now, first I have to give you a rap on the knuckles--if you had started this thread by stating what your problem was, you may have had it fixed by now. Ok, knuckle rap over.

Running rich: bad CTS tells PCM engine is cold, PCM increases duration of the injectors; bad o2 sensor tells PCM engine is lean, PCM increases duration of the injectors; the MAP and MAT will also provide input to the PCM that can cause the PCM to increase the duration of the injector pulse.

An exhaust leak, upstream of the o2 sensor(s) will cause the o2 sensor to send input to the PCM that the engine is running lean and the PCM will increase the injector pulse.

If your thermostat has taken a dump, and the engine is not reaching normal operating temp, then it may not go into closed loop and waste fuel.

I really thought it was the fuel filter. I've replaced o2 sensors recently and it only throws misfire codes at me.

I read in the 3rd part of that article that the a/c clutch pulley had failed and they said replacing it had improved their mileage. I know that my a/c no longer works but never determined what the issue was since it was at the end of summer and it wasn't going to be something simple that I could figure out at home.

I don't think that relates to a misfire though.

I also have noticed that my exhaust somewhat burps at idle speed when I stand behind the tailpipe.

Post exact codes here for best results.

A random misfire can be caused by a vacuum leak in the intake manifold, throtle body or vacuum plumbing. Other causes can include spark plugs and wires, ignition coil and fuel injectors. Fuel pressure is also suspect, but you verified that fuel pressure is okay at 50 psi.

gotta love how easy the earlier models are to replace