Hello,

My '94 XJ-S Conv 6 cyl will only take half (about 8 gallons) of the total capacity. I beleive there are two seperate but interconnected tanks. Could a connection tube or flapper valve be plugged or stuck closed? The fuel gauge is also intermittent (bad or sticking sending unit?), but sometimes indicates full. The range is now about 160 miles. Any ideas?

On the subject of the fuel gauge, I have a Jaguar SB 88-19 (thanks to this forum!) regarding some sending units with tight float rod bushings. Is this something that a Jaguar dealer will replace at no cost?

Thanks!

Mark

 

Hi Mark

Your car has one large tank, in the trunk, up against the bulkhead. I believe some earlier H&E convertibles had split tanks, but yours is a single piece.

When you say it will only take 8 gallons, does that mean the is fuel coming all the way up the filler neck and spilling out after 8 galllons? Or does it just become very, very difficult to fill ?

Did the car ever take the full amount (>20 gallons) or has it always been like this ? Do you know the history of the car.... ? Any "fuel issues" in its past?

My 92 car used to be extremely difficult to fill with fuel, but when I moved house I started filling up at a different station and the problem mysteriously went away......

 

A failure of some venting component could cause the system to create a vaccuum, and collapse the tank...but I would think you would have heard that!

Dave

 

Thank you both! I'll look into your suggestions.

 

First thing to check is if the tank is collapsed. However it would have to be significant if you can only get 8 gallons in it. More likely you have a venting issue when filling. This is done via the carbon canister. You can remove those lines make sure they are clear and leave the line open to atmosphere and go try to fill the tank. If it takes a full tank then you found your issue. Also as was mentioned try a different station. In my day job I have run across certain pumps that will click off too soon.

 

+1 to Greg's comment on the fuel vent system. Maybe worth temporarily disconnecting it from the charcoal canister if you continue to have issues.

As Sarc mentioned, only H&Es had the split tank due to the requirement for the 'low stack' with the top down. Jaguar lifted this requirement for the '89 and onwards factory convertibles.

Cheers,

- Will

 

I recon you have a similar problem to me...

When my XJS is empty, I can only get around 50 litres in it, it was only recently I learned the tank is actually 90 litres. This means my fuel gauge mut be inaccurate. I fill it up when the fuel light is on permanently and the needle is nearly on empty. I recon the gauge is out of calibration.

I plan to to a trial and drive around with a spare fuel can in the boot and see how far I can run the car until it runs out of fuel. I am guessing the fuel needle will probably drop out the bottom of the gauge before it runs out. I will let you know how I get on.

 

Darren
If you are going to run the tank right down then why not just change the sender unit whilst the tank is empty? As I recall they aren't too expensive and are dead simple to change.
Steve