Changing XJS Fuel pumps
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Changing XJS Fuel pumps
We've got a '95 XJS V12on whichboth fuel pumps have apparently failed. The car ran fine all last summer and has been garaged for the winter. It would not start when we tried this week. The local Jag dealer says BOTH pumps have failed (have no power). Is there circuit protection for these units?
My question is does anyone know where I can get the the instructions to R/R the pumps. From what I can see in the service manual (on CD) it looks like the fuel tank must be removed to access the FPM...can anyone offer tech advice or at least tell me where I can find a better service manual. I would greatly appreciate your input...so fire away...as the warmer it gets the more time my wife will spend on my back about getting her baby back on the road!!!
My question is does anyone know where I can get the the instructions to R/R the pumps. From what I can see in the service manual (on CD) it looks like the fuel tank must be removed to access the FPM...can anyone offer tech advice or at least tell me where I can find a better service manual. I would greatly appreciate your input...so fire away...as the warmer it gets the more time my wife will spend on my back about getting her baby back on the road!!!
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Joined: Mar 2007
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From: Florida
RE: Changing XJS Fuel pumps
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
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
Senior Member
Joined: May 2016
Posts: 351
Likes: 142
From: Dalton, GA
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
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
Veteran Member
Joined: Dec 2014
Posts: 1,892
Likes: 982
From: California
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
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.
Veteran Member
Joined: Apr 2014
Posts: 4,573
Likes: 3,520
From: Kent, UK
Hi OB,
No, it's not an error! Late XJS V12s (6.0 litres) have two fuel pumps located in the tank.
Cheers
Paul
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Joined: Jul 2010
Posts: 2,459
Likes: 695
From: Key West, FL
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)
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