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Fuel Filter

aplatz

NAXJA Forum User
Location
Frederick, MD.
Guys,

I have a '96 XJ w/ a 4.0l and bought a new fuel filter after 114k. Question, does the fuel system stay pressurized when the engine is off? My manual said pre-'96 were not since the fuel filter is not inside the gas tank. It's on the frame rail (I checked to make sure)

Yay or nay? Just pop off the hoses and be dome? Or depressurize?

Thx,

PLATZIE
 
Supposed to depressurize it at the fuel rail, atop the engine. There is a fitting like a tire valve (at least my 90 had one). Push in the pin, then have at it. (Oh yeah, you are still going to spill gas all over yourself when you pull off the filter. BTDT.:D
 
So even if you clamp off the hose ends, it'll spill from whats inside the filter? Does the system pressurize it self after ignition? Jiffy Lube wanted $30 to do it even though I already have the filter.
 
aplatz said:
So even if you clamp off the hose ends, it'll spill from whats inside the filter? Does the system pressurize it self after ignition? Jiffy Lube wanted $30 to do it even though I already have the filter.

Yup. Keep it relatively horizontal, and you shouldn't spill much. BTW, no smoking, please.....

Actually, the system pressurizes as soon as the key hits the on position, it doesn't wait for the engine to start running. It can't wait, without pressure (and thus, volume) there wouldn't be any fuel flow to the injectors at crank time.

Your manual (Haynes or Chiltons? :D ) is just plain wrong. Both my 92 and 94 stay well pressurized for some time after the engine shuts off.
 
I just changed the filter on my 96 XJ not to long ago. You'll definatley get a little bit of gas in both the lines that will spill out. It's not much so a small container or a bunch or rags is enough to absorb it. I first started the Jeep and then disconnected the fuel pump from under the Jeep with it running. When the Jeep died, I then depressurized the system at the rail. I also undid the gas cap.
Pretty simple, shouldn't take longer than 45min.
 
The new fuel filter should have a cap on each end. Use them to keep the fuel from spilling out of the old filter.
 
I should explain...

Take the caps off of the new filter. Then, as you remove the old filter, simply pop a cap on the end. That'll keep the fuel inside the old filter.

I use "vice-grips" to clamp the open fuel lines.

Definately depressurize at the fuel rail, at least.

June has an excellent method for really taking the pressure off...!
 
June said:
I just changed the filter on my 96 XJ not to long ago. You'll definatley get a little bit of gas in both the lines that will spill out. It's not much so a small container or a bunch or rags is enough to absorb it. I first started the Jeep and then disconnected the fuel pump from under the Jeep with it running. When the Jeep died, I then depressurized the system at the rail. I also undid the gas cap.
Pretty simple, shouldn't take longer than 45min.

Huh? Methinks you're overcomplicating things just a bit.

IIRC, the FSM says to depressurize the fuel system, just depress the Schrader valve on the fuel rail. Catch the squirt with a rag, and it's best to NOT do this with a hot engine, the exhaust manifold is right underneath. You'll only get a little squirt, well under a teaspoonful. No need to start the Jeep at all.

Besides, this WON'T drain the fuel lines at all. They're pressurized from the tank, and you won't suck much if anything out of the injectors when pressure goes.

I spilled less than a quarter cup when I changed mine, and it took me less than 15 minutes, including stowing all of the tools and washing up.
 
please forgive this thread jacking but,
I have been having some problems recently, i wanted to put a filter on my 98 that i could change easily. Can i just use a filter form a 96 and plumb it inline somewhere? How and where would be the best place for this?
thanks
 
Tom Campbell said:
please forgive this thread jacking but,
I have been having some problems recently, i wanted to put a filter on my 98 that i could change easily. Can i just use a filter form a 96 and plumb it inline somewhere? How and where would be the best place for this?
thanks

You could get a filter from an earlier year XJ and mount it to the frame rail, the same as the factory did. But the OEM filter for your year is integral with the fuel pump, inside the fuel tank. Your added filter will be redundant, and downstream of the OEM filter so it won't help protect/preserve the OEM filter at all.
 
would it be advisable or possible to remove the tank filter? or is an integral part of the pump? for instance if its just a screen or so could i just remove that and rely on the outer one to change? i dunno i think im gonna have to drop my tank soon and replace the pump anyways.
 
On the 97 and later models the regulator and filter are combined ,with the fuel pump in the tank.
To change the filter/regulator the tank need to be dropped out as the pump fits in from the top.
I have no idea of the cost of this filter/regulator but it is a servicable piece.
HTH
Wayne
 
may be serviceable but that seems like quite a chore. I'll have to battle gas skid bolts, bumper support bolts, etc.

Well can anyone tell me what ill encounter trying to lower the tank? what hoses to watch for and such? this will be a messy affair for sure...
Thanks and sorry again for hijacking the thread but i figuresd the topic is close enough.
 
Its about a 2hr job.A mech at the shop I help part time did one 2 wks ago.He did have a lift ,air tools and NO fuel in the tank.
No skid or hitch in the way either.Biggest problem I say was the dirt falling in his face.The J hooks on the tank straps were rusty and dirt coated,some PB spray could help things.
He replaced the whole fuel pump assembly.Had it running and out the door in 2hrs
Wayne
 
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