See post #17


https://www.jaguarforums.com/forum/x...needed-188498/

it’s what I did and has worked perfectly.

 

Well its back! now I'm getting code P0193 Fuel rail pressure sensor circuit High input? I am also getting a pending code for multiple cylinder misfires including #3 . I had switched out 3&5 with 1 &7 coils when I replaced the spark plugs. I had also replaced the fuel pressor sensor last time. I replaced it with the old one and no difference. One strange thing is I replaced was the coolant temp sensor with 2 Standard motor part replacements and the car refuses to run with ether new part. It seems like the engine is flooding with the new coolant sensor. If I replace it back with the old one the car eventually starts and runs fine after clearing out. I thought for sure I found the cause with the broken vacuum hose and massive air leak around the throttle body.

 

For what its worth, I also have a 2009 XKR with 64K miles on it and noticed the very same symptom at start up. It idles rough like it is missing on a few cylinders but then evens out within the first minute with no codes whatsoever. Since it remedies itself, even before it really has a chance to even heat up, my thoughts were that it was a sensor issue. I am going to clean the MAPP air sensors as my first attempt to correct it although I will check the rubber gaskets at the T now that I know it could be an issue.

Keep us informed as to the final outcome. You've got my attention!

 

Good luck keep me posted too. If I have any positive results I'll post it also!

 

As it does it very early on the car's not yet gone CL (closed loop), i.e. is not using the O2 sensors as they're not hot enough. So it has to trust what it can use (plus it wants a richer mixture a bit like the old days of a choke). If you want to hunt for a naughty sensor it's got to be one it's trusting such as the MAF.

It's worth first of all checking the trims with a hot engine at idle in case they're off as in that case a fix may well also fix the problem(s) when cold.