Fuel Pump Replacement

The noise doesn't seem to appear from a cold start, but after about 10 to 25 minutes of normal driving I begin to hear it regardless of whether the car is stopped or moving. I haven't really listened at high speed yet.
thanks

Don
94 XJS, V12, Coupe

The first question to answer is when the pump makes noise. If it does it at all times, including idle and low rpm's, then it is the primary. If it is at higher rpm's it is the secondary.

IIRC, you can switch the wiring on the two pumps. (There are in line connectors) See if the noise changes.

The pumps are removed and installed from the top of the tank. If you remove the panel behind the spare tire, you will see it. You will have to unfasten the mountings, and slide the tank out a bit, then possible tilt it so the top is toward the rear of the car. Take a look and you will see what I mean.

The parts manual shows the fuel pump as an assembly with the cover and other parts. The part you get from Autozone (or others) is the pump only. You will have to take the assembly apart to replace the pump.

BTW, I strongly suggest that you don't smoke while doing the job.

Maynard Hirsch
86 XJ6
91XJS
78MGB
67MGB

OK,two fuel pumps! This gets better all the time. First,is there a way to determine which pump may be failing? Second, when you say lean it forward do you mean tilt the bottom outward (towards the rear bumper) to get at either pump? Third, if one goes completely out, is the car dead on the road?
thanks

Don
94 XJS, V12, Coupe

Art Dickenson.
1983 XJS GT "Silver"
Pacific Jaguar.ca

Don, obviously Maaynard knows more about the newer V12's than I do, carry on, sock it to them Art

They are well meaning, but forget what the otehrs have said. The 94 V12 has two fuel pumps, both located in the tank. It also doesn't have a swirl tank, it was eliminated with the intank pumps.

The sock is attached to the fuel pump(s). When you pull the pumps, the socks come with it. They also come with the new pump.

You will have to unbolt the tank and slide it forward to remove the old pumps. I don't think you actually have to remove the tank from the car. Just be sure that you replace the correct pump.

Maynard Hirsch
94 XJS V12 coupe
86 XJ6
91XJS (RIP)
78MGB
67MGB

Art Dickenson.
1983 XJS GT "Silver"
Pacific Jaguar.ca

Ho Don,
the swirl tank is located downstream from the main tank, so you need to simply clamp the rubber hoses @ either side of the swirl tank. This tank is a bit of a nuisance to get at and normally gets neglected and not serviced for that reason. You do not need to drain the main tank, the swirl tanks reason is to maintain a constant supply of petrol during perhaps hard cornering with a low fuel tank to supply the fuel pump and maintain high pressure to the fuel injection system, send e mail I think I have a sml vid clip on this subject, Art silver007shaw.ca

Thanks. Does cleaning this sock require me to drain the fuel also? Is this a part of the fuel tank?

Don
94 XJS, V12, Coupe

Art Dickenson.
1983 XJS GT "Silver"
Pacific Jaguar.ca

Hi Don,
the problem may actually be the fuel sock in the swirl tank , this is located in the / under the battery box area @ the right rear in the boot, clamp the fuel lines with some kind if vice grip ( carefully so not to tear the rubber ) The sock is in the tank , afetr you get it out you may be able to just clean it . Replacing the fuel pump may not solve the groaning problem and pumps are not cheap.
Art