I am about to tackle this on my 97 which is coming on its 60K service. I bought the Mann 612/2 filter.


According to the service manual, you are first supposed to relieve fuel pressure at the Schrader [sic] valve in the engine compartment. If you did not do so, it may explain the excess fuel loss.

 

Hi Madbrad, I didn't do that cause it wasn't mentioned in this thread prior to you mentioning it.
I opened the fuel tank filler cap to releive the pressure.

However once I unscrewed one side of the filter, the pressure, if any remaining, seemed to have been released, then it would just keep trickling fuel whether the tank filler cap was open or closed, and it seems like it just would have kept on going, so I just reassembled the one side that i unscrewed.

Thanks alot,
Sid

 

Note: For the most part the folks here are very helpful and knowledgable. When 'researching' you should perform a proper search and read several threads on any one issue to get a comprehensive understanding.
I'd highly recommend you installing the JTIS service program if you are struggling with directions so you have the factory guide for any issue.
You will find it in the 'stickies'

It's understandable everyone has different levels of experience and we don't always document something that might seem obvious to one of us but not to another. I use a jeep forum, MBenz forum and jagforums, which from my experience has the best support of them all, they are all good but people here really pitch in.

 

I did the fuel filter R&R just the other day and yes a larger amount of fuel did come out of the line and filter when I removed it. The fuel that was expelled came from the filter the line from the tank and the line to the engine so a bit more than a cup. I should mention that I had a little less than a full tank of fuel and no fuel was leaking from the tank. I know this because I had the filter off for more than 10min.

 

I replaced mine today. Got about a cup of fuel. I did release the pressure using the schrader valve in the engine compartment.

 

Hi Johns55, the schrader valve is on the passenger side at the fuel rail where one connects the fuel pressure tester, and its like a tire valve right?

So to release the pressure is a special tool required or what do you do, just press the needle in like when you release air from a tire valve?

If yes, then does any fuel come out of it or what happens?

Thank you,
Sid

 

I had almost a full tank as well.

Did you first release the pressure via the schrader valve?

Do you think that even though i releived the pressure by removing the fuel tank filler cap, my scenario was because I didn't release the pressure via the schrader valve?

Thank you,
Sid

 

I have not done the filter replacement in this model yet...but removing the fuel tank filler cap would not relieve the pressure on the output side of the fuel pump. The fuel pump does not work by pressurizing the fuel tank.

 

Yes, passenger side on the fuel rail. Mine has a blue plastic cap like a tire valve cover. Unscrew that and using a screwdriver (I used a phillips head), just press the valve in. MAKE SURE to cover the valve with a cloth while pressing in the valve. If you don't, fuel will spray everywhere. Most of the fuel that came out of the filter area was from the filter itself.

 

That is due to the pressure in the system. You should either bleed off the pressure first, or do it after the car has sat for a significant period of time. The pressure will bleed off internally after time. I would do it after it has sat overnight. (Also, this way the exhaust system is cool! - don't turn on the key before you start, or it will re-pressurize the system. Also, unless you are a hard core purist, don't go to jag for filter ($99.95), Wix website will give you the part # for filter equivlant for less than $20!

 

Hi Johns55, thanks for clearing that up for me, much appreciated

So when I do that, I'm guessing I should just press the valve until fuel coming into the rag just feels like it's not releasing anymore fuel and that it sounds and feels like there no more or very little pressure being released at the valve right?

Thank you,
Sid

 

Yes, it only takes about 10 seconds and there is no more pressure. Don't forget to put the cap back on.

 

Sorry to hear that you have taken that position. I think you will be missing one of the great joys of motoring.

 

Hi Johns55, I have tried as instructed, released pressure at shrader valve a for over 15 seconds a few times to make sure, then unscrewed the filter connection on front side (engine/door side) of the inline fuel filter but still the fuel kept coming, so called Gus for advice, and waited for half a gallon then gave up.

I then called europarts where I purchased my fuel pump, asked if maybe the fuel pump may have a defect or something to do with this, or maybe I shut it off in the open position, so he answered that the way he does it is run the engine, then while the engine is running to pull the pump fuse and let engine run til it stalls, then try to start it again to make sure, then try to change the filter, and he said i may still get fuel but not very much.

So while I still had day light, I went back to do as he instructed, so the engine stalled and I tried again to make sure, the engine just cranked but wouldn't start, I then went to try to change the filter, but still the fuel kept coming, I let it go half a gallon, then transfered the fuel into a fuel container, then tried some more until my arm gave out from holding the line away from the filter to allow the fuel to come out, i just couldn't anymore, so I gave up and reassembled the line filter connection.

Why the fuel just keeps coming i cant figure out, I have 3/8 of a tank of fuel in the tank, the engine stalled, and the pump is off.

Thank you,
Sid

 

I have no clue as to why you are getting that much fuel. When the car is off, the fuel pump is not working, so all you should get is what is in the lines and the filter. I can't figure out where your fuel is coming from. Hopefully someone else might have an idea.

 

Hi Johns55, I am wondering if maybe the hose that is connected to the in tank pump may be cracked and allowing fuel to get through, hence bypassing the pump, I think the process is that the fuel goes through the strainer then into the pump which then pumps the fuel through the suspect hose to the fuel line holding the line filter.

If fuel was going through a cracked hose then with the pump off and without the required pump pressure, the engine would still shut off wouldn't it?

I guess that if the hose was cracked that the pressure may even be compromised and maybe even be triggering the restricted performance message/condition.

Maybe I should check the hose in the tank.

Thanks alot,
Sid

 

UPDATE:
Well, I checked the hose in the tank, also especially the part that is submerged below fuel, and it seems fine. So don't know why the fuel keeps coming when attempting to swap the old filter for a new one.

Maybe with so many knowledgeable people on this site, I may get an actual possible solution or cause, but so far nothing.

Thanks to those that offered proper procedure suggestions.

Sid

 

Hi I ordered 2 cans of BG-44k from an ebay seller with decent feedbacks, got them and noticed the label was stuck on the can a little off, opened it up then poured a clear liquid into my family van then took the other can and poured it in the Jag tank.

Prior to that I tried calling BG at the number posted at their website, but all i got was an infomercial recording for other useless non related stuff, then i called another number they suggested on their recording, still more stupid recorded infomercials, then i called one of their local distributors in Port St Lucie Florida and some woman answered that didn't know anything about the product and offered to have someone call me back the next day because everyone was out for training she said, so what kind of stupid way of running a company is this? How is it possible that one cannot contact BG by phone and yet they're selling their product like hot cakes?

So far I don't see any benefit to the possibly authentic/non-authentic BG-44k I received, the van gets the advertised fuel rating mileage but still idles a little rough after consuming almost a full tank mixed with the stuff and the Jag i can't really drive because of the restricted Performance issue.

So how can one tell if the BG-44k ordered online is authentic and not a dollar store injector cleaner can with a fake BG-44k label, and where does everyone raving about the stuff purchase a certain to be authentic BG-44k?

Thanks alot,
Sid

 

The update: as I mentioned above, i added a possible BG-44k, cleaned the MAF sensor with CRC MAF cleaner, and cleaned the Throttle Body with CRC throttle body cleaner by also stuffing the throttle body throat with a rag so that no dirt goes into the intake, then let everything dry overnight

The end result is that the car now drive worse, it idles more rough than ever, and sometimes when I raise the idle the restriced performance goes away for a bit and sometimes I can still hear a miss at 2000 rpm and sometimes not, and then the RP returns so I let it idle a bit then I shut the engine off.

I ordered a mini bluetooth ELM327 but it cant find the protocol for both my vehicle with the Torque light app.

Here is a link to the ELM327 i purchased, they sell for alot more on ebay and i got it in about a week, also this seller has many good reviews about this product and confirmed it will work on the 99 Jag XK8 and my Chrysler van, as it say in their ad as well... 2015 New Super Mini Bluetooth ELM327 OBD2 Diagnostic Scanner With Power Switch Works on Android Symbian Windows ELM 327-in Code Readers & Scan Tools from Automobiles & Motorcycles on Aliexpress.com | Alibaba Group

Thanks alot,
Sid

 

About the ELM327s, I don't think judging an ELM327 by price really guarantees anything considering many USA sellers sell marked up China stuff anyway and many do work fine from what I have read.

I have read the posts on this site about ELM327 that work but have yet to see a current link to a specific seller of an ELM327 that the poster claims really works.

I did see one list of some OBD2s that were stated as working/compatible but they were all pricey, so where are the ones purchased cheaply and claimed to work, who is the seller and where is the link? Seems to be alot of yak but without links to any specific model of any specific ELM327.

So how to really get one that works at the best possibe price?

While i wait for a possible response to hear from another member i will keep trying then post my results with a link to the sellers ad.

About the fuel filter, I have given up on the idea of changing it for now since it seems my Jag is the only one that spews out fuel continuously when I try to change the filter and I nor anyone else knows why thus far.

Thanks alot,
Sid