Guys, I could use some help here if you have any ideas.
I have a 2014 Jaguar XKR 5.0L Supercharged.
I get no Misfire codes at idle or at low speed.
Only when I get to around 50mph I get Misfires on all cylinders as well as random misfire code.
Car has new spark plugs, also new fuel injectors

 

Check the fuel pressure.

 

I am getting proper fuel pressure - I forgot to mention that I also just replaced the 2 high pressure fuel pumps as well.
Any other test I can do?

 

When the misfires occur, what DTCs are set?

 

PCM (Powertrain Control Module) ( 9 DTCs )
DTC Description Status
P0301-00 Cylinder 1 misfire detected Temporary
P0302-00 Cylinder 2 misfire detected Temporary
P0303-00 Cylinder 3 misfire detected Temporary
P0304-00 Cylinder 4 misfire detected Temporary
P0305-00 Cylinder 5 misfire detected Temporary
P0307-00 Cylinder 7 misfire detected Temporary
P0308-00 Cylinder 8 misfire detected Temporary
P0300-00 Random misfire detected Temporary

The codes clear when I drop the speed down or just go back to idle.

 

Besides the high-pressure fuel pumps, what other items have been replaced or recently serviced?

When the misfires occur, is the fuel pressure still being maintained?

 

I am not sure if the fuel pressure is dropping during the misfire.
I am going to have to either record the session on my scanner or have someone else drive while I look.

 

oem fuel pumps? injectors?

 

yes oem fuel pumps and injectors - Bosch

 

Have you ever changed the fuel filter?

 

No I have not changed the fuel filter. Is it in the gas tank or on the frame?

 

Contaminated fuel?

 

Blocked filter just forward of the tank on earlier XK models. Possibly not on the 5.0L models. Jaguar recommends BG44 to clean the fuel system twice in 15K. Other posts tend to think your CATS are blocked.

 

This one appears to be in the tank from what I see - just ordered one

 

Fuel filter and associated parts for an X150 listing on SNG Barratt, one of the forum sponsors:

 

But I don’t see any O2 sensor codes.

 

I do not get any CAT codes nor O2 codes at all.
I did one back pressure test which showed zero back pressure.
I may do another one just to double check.

 

@NBCat - Yes that is the fuel filter that I just ordered yesterday.

 

+1 on the fuel filter ontop of the fuel flange on the fuel tank, I've replaced mine its a PITA
if you want to check for leakage, lift up your rear seats, there is a rubber access panel which you can
smell and reach in and feel for fuel leakage.

 

​​​​​​if its leaking, its due to a clogged filter. Flange/filter is on the passenger side rear seat,
Lift up the center rear arm rest carefully, then lift up the passender sie seat by pulling from the bottom
rear of the seat, it will pop out. under neath that is a rubber cover which can be removed to reveal the
fuel filter and flange. the hole is too small to change the filter from, but there are a few options..​​​​​​

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