Gas gauge readings are all over the place on the 04 XJ8.
Get fuel, the level reading drops.
Often clear to empty, with the low fuel warning light illuminated.
W T F is wrong with the gauge?
B1202, B2627, C1986 code readings
Fuel pump on the way out?
If so what side is it on?
Always like to have an idea what is wrong.
How to fix it & what to expect, before starting.
Car runs fine just like it should, other than the goofy gauge readings.
Any ideas whats wrong, & how to fix?

 

As usual, Jaguar issued TSBs years ago (the ones nobody reads).

bob

 

Thanks for those TSB's.
So it's the sensor sender behind the driver?
The fuel pump is on the right side?
Both under the rear seat.
Or is it on the pump on the right side?
The vin is G24085 an early one made in 03.
On ebay looks like maybe replacing the pump, replaces both on the early Jaguars.
If so, i'll be saving for a new pump, for replacing as it has over a hundred thousand miles.

 

Possible bad connection on sender contacts.

Sender is clipped to side of pump.

Cleaning contacts may resolve the problem which is not new.

With pump and sender on the bench check continuity readings

before and after cleaning

 

Good information, i do appreciate it.
Pumps on the right side according to drawings.
May try cleaning the contacts, but if i pull the pump.
I'll replace it, the ones on the computer for the 04's.
Say that your gas gauge will read right again after installation.
As long as this is NOT AN INDICATION the pump is on its way out.
Things are fine, as i always zero the trip meter when i get fuel.
Or do you have to pull the pump to clean the contacts????????

 

B1202 indicates sender circuit is open circuit

I suggest that it would be best to remove pump and sender

but you may be able to remove just sender in situ.

I think you need to squeeze a clip on each side of the sender.

NB Code indicates could be wiring fault but not likely.

 

Sorry if I state the obvious ... but you do realise that there are two senders, one each side of the tank ?

 

That is why i am asking about things, i like to have an idea what i'm getting into, before hand.
The car runs fine, looking at Classic Jaguars parts site,.
Its hard to make out, just what is what, for what car
Tempted to ignore the gas gauge, as long as the pump works.
But this is just about the last of things to fix, and a working gauge is nice.
Which sender is it most likely to be, any ideas???
From what i can understand, an electric fuel pump motor assembly,.
Available on ebay can be installed to restore the pumps function, for less than $100.
Just trying to have the parts i need before i need them, so the car is just down to fix, & not waiting for the parts to finish.

 

Right ... the tank is saddle shaped and hangs down either side of the prop shaft. The fuel pump, which is in the RH part of the tank, does two things: i) it pumps fuel to the engine, and ii) it pumps fuel to two jet pumps one in each side of the tank and each of which picks up additional fuel and sends it over to the other side of the tank; it's a way of keeping the levels on each side roughly equal when the two sides are separated when the level is below the middle 'saddle' point of the tank.

There is a level sender for each side and their readings are averaged to get the gauge reading. Both sensors are connected to the Rear Electronic Module.

There are two circular apertures in the top of the tank. The one on the RHS houses the (electrical) fuel pump, the jet pump which sends fuel over to the LHS, and the RHS level sender. The one on the LHS houses a jet pump which sends fuel to the RHS, the LHS level sender, and ... but only in the case of the supercharged V8 ... a second electrical pump.

 

So the question is, what is malfunctioning, & how to repair.
Fuel pump is very important, the fuel gauge is much less important.
If the previous owner ran low on fuel often, would this wear out the jet pumps, trying to keep fuel level even?
Am i going to have to replace all three pumps to straighten things out long term?????

 

You say the car 'runs fine', so I don't see how there can be a problem with the pump, and as to any problem with the jet pumps I don't see how there can be a problem there, they don't have any moving parts.

Edit: Looking at the fault codes:
B120200 is Fuel pump module, level sender above threshold
Cause
i) Fuel level float stuck/sticking;
ii) Fuel level sender circuit: high resistance
iii) Fuel level sender failure



B262700 is Fuel transfer pump, level sender above threshold
i) Fuel level float stuck/sticking
ii) Fuel level sender circuit: high resistance
iii) Fuel level sender failure

C1986 seems unrelated; it's something to do with the power steering.

So not the pump itself... it's one (or both) of the level senders.

 

The gauge has been an issue since i bought it, & like most things its getting worse instead of better.
From the looks of things $300 should handle the problem, till the pump takes a ****.
That is just too much cash at this time to put out.
Has anyone tried this pump motor on an 04 for when i need one???

New AC Delco Fuel Pump 93-08 Jaguar S-Type Vanden Plas XJ8 XJR XJS XK8 X-Type

 

If you go back to the post by Motorcarman, read and follow the first Jag technical bulletin attached to his post...

 

Doesn't do me a lot of good without the equipment to hook up

 

You don't need to hook up any equipment
Follow steps 1, 3, 4,5, 6 & 7
This will test/tell you whether the sender from each side of the tank is reading correctly by putting the instrument cluster into 'Engineering Test Mode'

 

OK, so i saw step 2,then believed i needed the special equipment to proceed
Will study, & start looking at things.
But with the fuel pressure at 55 psi.
Its more of a pain i the ***.
Than a real issue at this point.
Much appreciated

 

Picked up this pump motor to replace mine when i dig into this issue.
Sure hope it will fit & work, anyone know if it will??????????

Delphi Fuel Pump Kit DEL38-K4014 For Ford Lincoln Mercury Mazda Jaguar Nissan