Hello all, not really sure what is going on with my car, but I just tried to fill it up and only got 10 gallons in? The gas bubbles and spurts out if I try to fill it in anymore. It's my understanding that the 2000 XJ8 can take up to 21 gallons.

Also, I would assume that the fuel gauge would show only half full if it had some kind of tank issue, but it shows up as full. I also can't push the pump all the way in because it clicks and deactivates as if the tank was full. I can only fill it up if I put insert the tip of the pump in and hold it there until it spurts out.

The car CAN hold more than 10 gallons right? Is the other tank messed up? I tried finding solutions on here but there isn't any situation that matches mine exactly.

Any input is appreciated thank you.

 

There is only one float. It is not that straight forward indicating half full if there is fault. How many miles you can drive it before it shows half full ? Drive it untill it is empty and what gauge tells then ? With jerrycan of course.

 

There is only one tank, I've never put a full 20 gallons in mine, but I've almost never had to stop at 10 if I'm at a half tank to start with. The gas tank is definitely much bigger than 10 gallons.

There should be some kind of venting pipe or valve that allows air to escape the tank while you're filling it, otherwise the air pressure gets too high inside and it shuts off the gas pump. I don't know where this plumbing resides, but I'd be willing to bet you maybe have a kinked hose or maybe a valve in that line that is stuck shut, or it might go to a charcoal canister of some sort that needs to be replaced. Hopefully someone who knows more about it will chime in. Keep searching on google, you'll probably find the info somewhere.

 

I believe the gas tank capacity is 23.1 gallons There's a cannister vent valve that is probably stuck closed.
It's located under the car, on the passenger's side, at the rear of the right charcoal cannister. There is a
sticker on it with the part number... I think it is a Denso part..

 

Jaguar addressed this issue a few decades ago. Here is a TSB. (the ones that nobody reads)

 

And another..........................

 

I have had five 308 Jaguars and still have three. Four of them had no trouble with the gas gauge. The 2000 VDP that I drive has the same problem as yours. If you drive it until the light comes on and then stop for gas, it will only take about 10-10.5 gallons. I have tried to continue to put fuel into the tank but eventually it's up to the neck of the tank so I'm sure the tank is full. I fill it when the gauge is in the yellow and do not continue to drive much further as I'm uncomfortable driving it when I'm not sure how much gas is in the tank.
I assume there's something wrong with the level sender but I won't replace it considering the difficulty getting the tank out of the car! When I ever do replace it, I'll be replacing the fuel pump too.

So at least there are two of us that have the same problem....

 

I had that issue with my 95 XJ6. Rotating the nozzle 180 deg allowed a compete fill.

 

I read those TSBs and decided to look into the gas gauge problem. The gauge showed very empty with the light on so I measured the tank sender pins which showed 387Ω. I then filled the car to the very top and it took 11.33 gallons. When I returned the reading was 83 Ω indicating full tank. I was able to fill the tank to the top so I don't think the vent system is clogged. The reading of 387 is about half way between 80 and 900Ω which should show about half full on the gauge. I'm wondering if the instrument cluster is just indicating the level incorrectly? If so, I'll swap it with one I have around here sometime soon to verify. I may get a 1K potentiometer from work tomorrow and connect it to see how the gauge reacts when I turn the wiper from minimum to maximum. I might not get a chance to fool with it as I will be busy for the next couple of weeks but I'll let everyone know when I do get back to it. In the mean time, I'll drive the car as-is since it's been like that for a long time.
Best, D

 

Wasn't the sender positioned towards the trunk, not the rear window? Or do I remember wrong ? If not, then it is very easy to remove sender and measure it.

 

It appears the sender could be removed rather easily but at the moment the car is full of gas! Taking it apart right now would be a gas problem for sure...
I'll drive in until I have about 350 more miles and then recheck the resistance. Will let you know what I find.

 

Hi Guys and thanks for all the useful info. Just purchased a 3.2 XJ8 (308) 2001 and having many of the problems you have outlined here. Gauge showed zero and warning light on when took it from the dealer (no surprise there), put 3 gallons in (with no issues) just to get me home and gauge still showed zero and warning light, so a little surprised.

Next day was intending to put 10 or so gallons in and had a real nightmare filling her up. Pump kept cutting out all through the fill (had to keep nozzle very high on the fill tube) and only got about 8 gallons in before fuel overflowed from a definitely full tank. OK . . gauge clearly not reading correctly, but rather pleased I had more fuel in when collecting the car than I thought. Gauge still reads zero and warning light on but tank (21 gallons ish) definitely full.

I'm going to explore all possibilities you have identified and already made mental note to use a different pump-fill next time and change angle of pump gun in fill neck. I was hoping that it might be a sticky float arm that might spring back to life now the car has some decent level of fuel and being driven.

I'll let you know of progress . . . and Cheers Again for a tremendously helpful thread.
StokeMusicDude

 

Best of luck to you!

 

The tank holds 23.5 gallons or so. My gauge shows it's very low even when mostly full; it shows full when filled up. At the point the light comes on, it will take only about 12-13 gallons. You can measure the ohms at the sender on the back of the tank as described in PDF labeled "Fuel Tank Faults". See the other PDF for the place to check the readings. When full it should be about 80 ohms. Empty is 900. My car must need a new sender but I'll probably not fool with changing it as I know when to fill up! It sounds like either the sender is not working or you have a break in the wire from the tank to the instrument cluster! Or maybe the cluster is having a problem? I'd start with checking the sender reading first.....