2007 XK 4.2 65K: Car does not have inspection cover under rear seat to remove fuel pump. Going to cut one. Anyone have details of the position of this cover which is standard on later XK's

 

Correction: the dealer says remove tank. inspection shows 5" hole right side rear seat with access to the fuel pump. lets call it a "misunderstanding".

 

Does anyone know the location of this item on the car. Trunk side panels? Do not see it in the battery area at behind the trunk panel.

 

2007 Xk 4.2 65K ealer analysis of codes etc, low fuel pressure.dealer advises change fuel pump. Symptoms: Always starts and idles perfectly: Opening throttle, engine responds with approx 1 second noticeable variable delay: Engine surges to meet throttle opening, hesitates and surges again. Very noticeable above 4000 rpm. Vehicle has always run out of power around 4000rpm will reach 6000 but its not pushing hard.After 1 year finally decided to fix the problem by holding it at 6000rpm for a few minutes. Result was a lot of jerking and pinking noises. Now the surging is much worse and at lower revs but still starts and idles perfectly. Suspect crap in the tank pulled into the pump as downstream filter checked OK. The pump has two suction lines which i now think both pull from the opposite side of the tank to the fuel pump. If I understand the fuel system correctly the injector solenoids can be seen a variable flow valves if the upstream pressure surges to 55 psi and then reduces due to fuel problems the engine must surge driven by the fuel pressure rather than the injectors. No codes on the panel which disappointed me, dealer says that is normal for fuel pressure problems. Members comments would be appreciated>

 

The fuel pump in controled by the ECU, but there is a small electronic fuel pump driver module on the right side of the evaporative charcoal canister. The EVAP charcoal canister is on the outside of the fuel tank, just behind the spare tire well.

 

Thanks for the info. It is hard to find things in that location but will persist if swapping the fuel pump does not fix my pressure problems

 

Another area not to be overlooked is the fuel filter, located on the chassis, just forward of the gas tank.

 

It is very easy to check fuel pressure - use a ScanGauge or equivalent connected to your OBD II port.

If your fuel pressure is low, suggest you try the cheapest and most expedient remedy first: change the fuel filter. You did not mention whether or not you ever changed this filter; and at about 65K miles you could be due for a filter change. Whatever, my opinion is that clogged fuel filters unduly strain fuel pumps, which leads also to fuel pump failure. My point is that don't be surprised that a fuel filter change alone does not cure the problem.

 

Kudos to the suggestion of using a OBDII scanner
to look at the rail pressure.