unless the dealer is proven correct, I would not believe that BOTH pumps would fail at the same time, I have two old Jaguars and those pumps never go bad from lack of use. (mine are 40-year old and 22 -year old pumps). Something else must be keeping the car from starting, My generic advice is for example:

is there gasoline in the tank? (wouldn't be the first time a car is out of gas and it doesn't start, prompting the owner to call a tow truck to have the car taken to the dealer!), is there something as simple as a FUSE for the fuel pump(s) that has not been checked and may be blown? (check your Owners Manual for the locations). Have you rocked all FUSES in their sockets? (sometimes fuses loose contact by just sitting there and by humidity creating a barrier). Fuel Pump RELAY checked? Do you hear it or feel it click when you turn the ignition switch to ON? Is the INERTIA FUEL CUTOFF SWITCH tripped? Fuel FILTER clogged? (it happens but I doubt it!) All Ignition WIRES seated correctly? (especially the one to the ignition CAP and to the COIL). The COIL itself? (12 cylinder cars love to kill Coils). Look for anything disconnected in the engine compartment, sometimes just LOOKING finds things. "Seek and you shall find".

Do the above homework on your own so that you don't get charged mucho dinero for checking the silly things! Then you can proudly give a list to the mechanic of things you already checked.

NOTE: there is a primitive (and dangerous) way to check if the pumps are working: It takes three people, one to crank the car, another to be ready with a fire extinguisher or a full pail of water, and one to disconnect one of the hoses at the FUEL FILTER. NO SMOKING! Here's what I've done to test if the pumps are pumping:

I take a bunch of rags and place them under/around the fuel filter, then I carefully disconnect the fuel filter hose coming from the tank keeping the hose away from my face and body because the fuel system is normally PRESSURIZED!, (some fuel will spill), I tell the other person to crank the engine while holding the hose down away from my face; Best to wear gloves. Gasoline is cancerous.
---the third person is standing by you in case of an accident---

If no fuel under pressure comes out of that hose when cranking the car, then the fuel pump is not pumping or the INERTIA FUEL CUTOFF SWITCH might have tripped (fuel system is then DE-pressurized, no fuel is being pumped) and needs to be reset by pushing the reset button down. If you don't know where all those components are located, check your service manual.

If you have the Factory CD Service Manual, there's nothing better unless you get an experienced mechanic to check the car, and the dealer is usually not the place where he/she will be. (there are exceptions). Chilton manuals sold by autoparts stores are a joke, don't bother.

good luck and be careful with the gasoline!
Jose

 

Good article. I thought the fuel system is always pressurized even when the key is off?

 

Hi

Are you sure your Car has got TWO Fuel Pumps?

Could you ask the garage where they found the Second one.

 

Ha, funny this should get bumped today.

On my '90 V12 donor car (75k miles) that has been sitting for at least 7 years, I thought I'd drain the fuel tank. Easiest way I have done on other cars is to power the pump and just drain it out.

Well, I discovered the fuel pump (CBC5657) is completely dead. Took it out, tried to power it, nothing.

So what I am wondering is this: could sitting for years kill it? Or, more interesting, was the car abandoned because it was not running, and the owner at the time didn't know it was just a dead fuel pump? That would be good for me if that were the major reason it was parked.

Oh, and turns out the gas tank was pretty much empty already. A hose around the filter seems to have failed and leaked the gas away over the years. Good thing I don't smoke - still had puddles in the boot.

Padre

 

If the PO didn't realize the tank had leaked out or evaporated out, he could have burned out the fuel pump trying to start the car. Then notices that the fuel gauge is on E, puts in a can of gas but it's too late.

 

Hi OB,

No, it's not an error! Late XJS V12s (6.0 litres) have two fuel pumps located in the tank.

Cheers

Paul

 

It was stated oddly. If the fuel system is shut down the system will depressurize by trying to crank it. You are dumping the fuel in the lines through the injectors to drop pressure.

There can still be some but its nothing like the blast in the face you get with a injection system at pressure.

 

As Paul correctly states post 93 V12 (6.0) have two fuel pumps, however at startup only one works , the second pump is switched on above 2840rpm to help with fuel demand at higher revs . As well as inertia switch (passenger door / footwell on UK rhd) I would look for fuel pump relay fault (near ecu in boot / trunk on right)