Yea, I was wondering about that too. See post #54 above. I haven't done any troubleshooting though.

 

I finally bit the bullet and brought the car to a Jaguar specialist... They installed a new charcoal canister assembly, along with other "while you're at it" jobs like e-diff fluid, brake fluid, replacing worn suspension bits etc. The car passed all applicable tests in SDD.

It did not fix the issue... I asked them to put in 20 gallons since I dropped off the car empty, and received a call as I was on my way to pick it up, letting me know that they were STILL unable to get fuel into the tank. DAMN IT.

So now I'm $4k poorer, and the car still has the same fueling issue.

At this point I'm devastated and at a loss with how to proceed. Dropping the tank again will likely be another $1600 in labor plus parts.

A new fuel tank is $2K... And I have a feeling it also won't resolve the problem.

Something is preventing air from escaping the tank, and my Hail Mary effort didn't work...

It's very difficult to justify spending nearly $8k on this problem if it comes down to it. A used tank is $350 on eBay.

Is there anything internal to the tank that would cause this issue? Are there any other tests we can try? I suggested blowing air or using a mighty-vac on various vent tubes to determine if there's a clog in one of them.

 

You could always spear the tank. That is, make a hole on the top somewhere and run a small tube to the outside. Best if it also goes through a carbon filter, but a used fridge filter would work. So would a fish tank filter of some manner. You could also drop a tube down the filler neck a couple feet while you refill. That sometimes gets gurgly though.
Sucks the "correct fix" didn't work.

 

. Have the same problem after 15,000 miles on my 2010XK. I feel like a jerk babying in the gas to get 8 gallons in. Next time I’ll find a more isolated gas station other than my wholesale club so that I don’t get angry people staring at me! I’m not attempting to drop my gas tank with as little driving as I do. I guess I’ll learn to live with it and not wait for the tank to get too low.

 

This week I let the fuel drop to 20 miles of remaining range and the car took 15 gallons no problem, twice now. NAS SC car.

I'm going to get into the engine mounted purge valve and see it I can tell if it's working.

 

Wouldn't this affect the ability of the DMTL pump to pressurize the tank? It would think there's an evaporative leak.

I wouldn't be able to use any kind of drill either because of debris, so there's an added possibility I'd dent the tank rather than pierce it. It could be double wall (someone must know if that's true or not). Also, I'd need to seal it VERY well, and ensure it would last for years. It's no small task to reliably sealing a hole in a smooth metal surface to a flexible tube.

It would also allow fuel vapor to constantly vent to atmosphere, which would cause the car and garage to have a strong fuel odor.

The fuel enters the tank from the bottom, so it doesn't spill out during a rollover. This means threading a bleeder hose down the filler neck would need to make its way up into the air pocket at the top of the tank. Given the difficulty I had just getting a borescope into the neck, this seems impossible to do every time go to the gas station.

Either way, puncturing the fuel tank to add a diy vent tube and fish tank filter doesn't sound like a safe or advisable solution.

 

Yeah, I just blabbed about the Old Man ways we used to fix this problem.
Disregard! Too many unnecessary "improvements" to make a simple system into a complicated mess.
I don't know about the 'fill from the bottom' thing though, that'd make it MORE susceptible to stopping the pump at refuel, plus Fuel Caps do that same thing. I've never researched these tanks.

 

It shouldn't make it more susceptible to stopping, due to the simple physics. Correct me if I'm wrong...

If you punch a hole in the side of a cup, near the bottom, and insert a straw from the outside... The liquid level poured in through the straw, and the liquid level in the cup will always equalize as long as the air in the cup that's being displaced by the added liquid has somewhere to go (atmosphere).

If you seal the cup, no liquid will go into the straw because the displaced air would have no path to escape.

 

The only place FOR the air to escape would be through the Evap Canister. That's a small diameter escape and it's already partially or fully blocked because that's the subject of this thread, or there wouldn't be a problem.
Do your straw in a cup thing but have only a pinhole size vent on top of the otherwise sealed cup. Yeah, it'll fill the straw up much faster than if the liquid was in freefall from the top of the cup.

 

We're saying the same thing. My point with the cup and straw example was to demonstrate that the fuel port being on the bottom of the tank doesn't affect the ability of fuel to enter the tank any more than if it entered from the top.

The flow rate is limited by the diameter of the straw since it's a gravity fed system, and that the air can exit at the same rate fuel enters. They will equalize no matter what, as long as the displaced air has a path to escape.

 

It again relies on the CFM rating OF that escape path compared to the CFM of the input. Liquid pushing against liquid to enter a vessel if far less efficient than liquid pushing against air to fill that same vessel.
I don't believe the fill tube goes to the bottom. There is no benefit. The Rollover Scenario is an argument, but it's not a valid argument in a closed system.
Therefore, this discussion for this thread is moot.

 

The fill tube definitely goes to the bottom.

It's been standard automotive design practice to fill tanks from the bottom for safety requirements and regulations for as long as I can remember... I say that from professional experience. CFR2013 Title 49, Vol 5, Section 393.67

https://www.govinfo.gov/content/pkg/CFR-2013-title49-vol5/pdf/CFR-2013-title49-vol5-sec393-67.pdf

Totally agree that this 'debate' is derailing the thread into discussion that doesn't work towards resolving the issue. Thanks for your contribution.

 

Okay, correct on the Hijack part since we're neither helping.
Certainly no STANDARD though, and I've never dropped any tank that filled from the bottom of the probably close to 80 I've done. This was the last I did, a 2022 F150 about eight months ago because my neighbor's Kids and Rocks. His truck.. Fills at the top, no inside tube:


It would seem MORE dangerous to me to have the inlet at the bottom with a coupling down there. Only like 3% of all vehicular mishaps are roll-over. That a vastly higher number of possible decoupling problems where ALL the fuel would evacuate due to positioning and a decouple.

 

Actually probably closer to 40 tanks dropped, I over-stated a bit. Installed far fewer though... Ten maybe? I helped out at a scrap yard for awhile.

 

Regardless of where the fuel goes into the tank, there MUST be some system in place that prevents fuel from leaking out in the event of a rollover. I believe it's also standard practice for vehicles to have a rollover valve that closes and seals the tank, and some vehicles have a manual reset button that opens the valve back up. I believe the X150 doesn't have a reset button, and no way to know if it's been triggered.

The rollover valve is located inside the LVS. It's a passive system, as there's no wiring for it. I do not believe the LVS can be diagnosed as being faulty, which could be the reason why a full tank swap is general repair procedure.

 

Im having the same problems & was about to have the carbon canister changed out. I’m now wondering if it’s possible to access the 2 vent lines on top of the tank & disconnect the hoses & then try filling the tank. Failure to fill would then point to the liquid vapour separator. Im also wondering if it’s not a vent problem, but a fill problem. The tank inlet has a check valve that opens under the weight of fuel in the fill line, what if this is sticking? ( part 12 in your post No.24) Drawings suggest it’s in the tank, secured by an o ring, I’ve not seen a part number for it, however in your post 72 photo of the fuel tank, I wonder if that’s it sticking out? Could this be rodded open via the fill line or accessed by dropping the fill line out?

 

It would be really helpful if someone could comment with a way to verify if the tank is operating properly.

This is my understanding of the system... Please correct me if I'm wrong.

The two ports on top of the tank serve different purposes. The drivers side port (NAS vehicle) is the air inlet for the DMTL pump to pressurize the tank. I'm not sure if there's a check valve on this side. It's connected to the passenger side port inside the fuel tank, via the tee from the LVS. The passenger side port acts as a vent, where the line travels along the filler neck and terminates at the pump nozzle inlet.



I would like to know if suction can be applied to either port while the other is closed. Air should come into the tank from the filler cap (it needs to be open), and flow freely through the system. If any of the LVS valves are stuck, you would pull a vacuum instead.

I don't think the LVS is a serviceable item, which would warrant a tank replacement.

The charcoal canister has two ports, the larger tube sends air from the DMTL pump, and goes into the driver's side tank port to pressurize the tank for an evaporative leak test. The smaller tube goes to the purge valve under the hood.

The tube coming off the DMTL pump is an inlet that draws air from the small filter zip tied near the nozzle inlet.



If the fuel inlet check valve is sticking, I don't think it can be serviced or removed. Based on my limited manufacturing knowledge, I would bet that the LVS, valves, baffles, etc are attached to the inside of the tank half before they are cold welded together. That's just a guess, though. I can't see how someone could reach inside the tank to remove any of those items or replace them. I'd love to be proven wrong, though.

 

I'm having the same issue with my 2012 XK. I now have 87,000 mile on it. Mine clicks off whether I pump it in the morning or at night, whether It's cols or hot out. Whether I pump it slow or fast, whether I go to the same station or one of a hundred different stations. I now just take the extra time needed to slowly pump the needed amount of gas into her. I don't care if people are behind me at the pump or not. She's 11 years old and in need of care like an old mother. We all get old and things wear out. I'm tired of dumping good money after bad into it. New Suspension. New Water Cooling System (Water Pump, Thermostat, Cooling Hoses & Pipes, New Radiator Fan). New Paint Job. Now this?
It also needs a new Front Passenger Side Headlight (LED Riding Light Strip is out) - $1,650 used.
Major Road Rash on Driver's side rim and some light scratches on the other 3 rims. Because of the Black Powder Coating all 4 need to be stripped and repainted to match. - $1,000
I've decided to fix her up by taking care of the rims and maybe the headlight and sell her. I'll put a half a tank in her before doing so, this way the new owner won't figure out the tank filling issue for 3 days or more and it'll be his problem to fix.

 

If that’s your strategy, you might want to give it a full tank, as the new owner might be through that half tank in a couple hours.
I haven’t had trouble with my fill-ups since I let it run down to close to empty, then it sat for a few days before refilling. Think the canister dried out enough over that time to resume its normal operation.
Might be worth a try.

 

rant
This is problematic to me. Did they test the canister before replacing it to see if it was clogged? Did they do any diagnosis on the venting while the whole **** show was apart?? That would be the perfect time to find the issue. The problem is that a specialist can't figure it out. Nothing against the specialist but against the design. My guy couldn't find a problem either and when he was done looking around, it started working! Until it failed again 3 months later. The EVAP systems in all newer cars are over complicated expensive bullsh!t IMO. What makes it 100 times worse is that this unreliable system is buried! It's insane.
/rant

Like I said earlier, I haven't had any time to mess around with it either so I live with it for now. Maybe forever!