The first time? Yes.

​​​​​​But I'm sure you can imagine my joy as I was prepared to spend 15 minutes filling up and suddenly noticed the gallons going in without stopping. I might have did a happy dance right there at the gas station... But that security footage has been lost.

The second time? No, because it was purposeful.

Please do report back. This will be an interesting data point. Hopefully saving at least one person thousands in repair costs.

 

Yes, indeed, and happy to do so. :-)

Thanks again.

B

 

I’m still confused about the carbon canister theory. Looking at the previous diagrams the liquid / vapour separator seems to have a common outlet that splits 2 ways, one going to the canister the other to the filler neck vent. Surely with the engine off the evap solenoid will be shut to the engine, which must rules that out?

 

The system is very overly complicated for what it does.
The canister lets fuel vapor and air that's in the 'empty' tank escape, making room for fuel to be installed. If the 'air' can't escape the tank, the fuel can't go in.
The canister is what allows the 'air' to escape so fuel can enter, it contains carbon and other stuff to treat the exiting 'air' to be kind to the environment.
If the canister gets clogged, still no air can escape, therefore fuel cannot enter without a gurgle at the filler hole. Fuel pump handles don't like that gurgle, so they shut off.
It's all down to the canister getting saturated or plugged.

 

So does all vapour leaving the tank go through the canister? The diagrams in post 24 show a common line leaving the tank but then splitting, one to the canister & engine, the other I would think bypasses the canister going to the filler neck. If it didn’t bypass the canister there would be no need to split it ( although it is Jaguar )

edit..
After going the the post 24 drawings again, in the system description it says, if you’re not NA then it should flow freely to the filler pipe opening.

Fuel vapor is generated by the fuel in the tank and the amount of vapor produced increases as the fuel heats up. Fuel vapor can flow freely to the EVAP canister via the tank venting system.
On NAS vehicles the vapor generated in the fuel tank during refueling flows without restriction to the EVAP canister.
On all vehicles except NAS, the vapor is restricted in its path to the EVAP canister, but can flow freely during the refueling operation to atmosphere via the fuel filler pipe opening

 

There's a pipe with liquid in the way of the vapor, which makes the liquid back up in the filler neck and shut off the pump. That IS the problem.

 

OK, so I drove my XK down to a reported range of 8 miles, which was VERY LOW. Started to fill the tank and it shut off immediately and repeatedly. Darn!

However, after much experimenting and a couple dozen shut-offs, I found that the pump would stay ON at the very slowest fill rate. How slow? The price numbers were barely scrolling by, which is saying something at $5.49/gallon. In any event, exceeding 1gal/minute, the pump would shut off. With an empty to full volume of 17.2gal, about 18 minutes. Not great but, hey, a time to contemplate, relax, whatever. I think normal rate would be 3-4gal/min.

If I don't let fuel drop below 1/4 tank, figure I'm looking at a 10-12 minute fill-up, certainly livable. Thanks for the suggestion on dropping down so low, it may be worth a try for others having the same difficulty!

Cheers!

 

Thanks for reporting back! It was worth a try... I'm still not sure why it worked twice for me.

I think your fill rate matches what I was able to achieve when the issue was present on my car. If it does eventually fail permanently, it will not be a surprise, so at least I can budget accordingly.

 

Just to add another data point... My low fuel warning light came on during a drive where I wasn't paying attention. I made it to a had station within minutes, but fuel wouldn't go into the tank without backing up into the line and forcing the pump to shut off every few seconds. Looks like the issue returned...

I put a few gallons in as an experiment, and drove around during the week until it was about 20 miles to empty, and sure enough, the tank began venting and a full tank of gas went in without stopping during my next attempt to refuel. Success!

Something inside the tank clearly doesn't like when the fuel level gets below 1/4 full, but "resets" itself, so the tank vent is able to reopen when the fuel level is VERY low, well beyond the low fuel warning light turning on.

This 'fix' has now worked for me at least 4 times during the course of ownership... Maybe I'm on borrowed time at this point, but hopefully it can save someone from the costly and time consuming job of pulling out the tank to replace items.

 

I tried the "very low" trick once more to no avail. :-(

I loved driving the car but, over time it became an expensive garage queen so I gave up and sold it a couple months ago, to Carmax. I disclosed the filling issue and their agent was not worried about it. They have greater capability and capacity to drop the rear-end and deal with this goofy design than I do/did.

Wishing you all smooth sailing and quick fill-ups! For me, I chose another road less traveled. Ah well...

 

Does another road less traveled mean a different brand?

 

Noticed this thread and thought I'd pipe in with my experience. I ran into this problem several months back and it drove me crazy. Heard the same story from the local indie shop about how expensive a repair it was but was told it will sometimes resolve on its own. Lived with it for months and never filled more than a quarter tank or so because of the frustration. Then one day my wife drove the car and filled it all the way up despite it probably taking half an hour or more. I drove it until the low fuel light came on again, and lo and behold, it filled normally and has continued to ever since. I don't know enough to posit why, but figured I'd share.

 

I’m uk based & this is a regular occurrence for me. Not sure I would recommend it, but my workaround at the moment is to fill the car with the engine running. Works a charm. I think the US cars have a slightly different set up that checks the pressurisation of the tank for vapour emissions. But so far no codes thrown. Have tried engine off & constant clicking, you can hear the fuel level rising in the fill tube as it struggles to get in the tank. Jump in & engine start, immediately no problems.

 

Very interesting.....
when I was researching the evap system, I noticed there was a valve of some sort under the hood in the circuit (that's actually easy to get to). I don't have it in front of me but I wonder if that has something to do with this (if it helps that the engine is running, that is).

 

Stupid question but are you filling up at a BP station?

My XKR has issues filling up with BP pumps.

Ive had similar problems on my VDP .

I just avoid BP now and the problem has never repeated itself.

 

Chevron or Shell. I've tried different stations as well in the beginning but that doesn't seem to be the source, at least not for me.

 

Wanted to update this thread I was participating in... The fix has stopped working.

I ran the tank to near empty twice, and both times still needed to add fuel in painfully slow 0.3 gallon increments.

Next step is to drop the entire rear drivetrain and replace the charcoal canister solenoid module.

 

I generally get fuel when the tank is between 1/2 and 3/4. My only solution to this constant annoyance is as mentioned above. I hold the nozzel and allow the smallest amount of fuel in at a time. So far no one waiting online gets pissed, but since my tank is usually no more than 1/2 down, it doesn't take all that long. Nothing is perfect, and I'm not dropping gas tanks for a stubborn fill up. End of case.

 

Leaving the engine running whilst filling is still working for me. Not a long term solution & I’m planning to get the rear end dropped out this winter.

 

Look at post #24, above. Or, pg 1855 in the 4.2 NA service manual. On the 4.2 (NA and SC, and in North America) SDD has a EVAP fuel vapor system and DMTL pump test routine.

For those who don't know, the EVAP valve on the side of the engine switches open once in awhile (there's a sequence of engine operation that triggers it, and then shuts it off) sucking fuel vapor out of the canister and feeding it into the throttle body.

If this valve doesn't work, the canister should get saturated with fuel vapor and tank pressure buids up or has nowhere to go when you're filling the tank. Does this jam it up? Not sure, but seems probable. If the DMTL pump fails, again the tank pressure increases when fueling and fueling is made more difficult. Detailed operations are on the page above.

On the 4.2, the charcoal canister and DMTL pump is outside the fuel tank.

Note the 5.0 uses a different system.