What have you done in regards to swapping coils around? Also, Have you actually watched the fuel trims at startup? I would want to see if there is a huge swing in the STFT after turning the key, perhaps its corrected after warmup, and not enough to change LTFT to set its own CEL code (i'm thinking like a TB gasket or o-ring seal expanding quickly).

 

I have run two cans of BG44 through the gas tank. The problem seems to have gone away. However, at the same time that the BG44 was being used the gas stations changed from their winter blend to their summer blend. I am not sure which had a bigger effect.

The car is at my dealer right now for an electrical switch issue. I will find out tomorrow if my misfire codes are still showing up. I don't feel any misfires or rough idling, but I am curious what the computer has stored in it's memory.

 

Just got the car back from the dealer and there were no codes stored for misfires. The last time they were cleared was three and a half weeks ago. So far so good. I will just have to keep an eye on it and see if the problem comes back next winter when the gas changes again.

 

I' ve had the same problem, went to the dealer, let them reset the faultcodes.
Then drove around for two days, and then let them read out the car again.

They found out it was the gasoline pressure sensor just behind the oilrefillcap easy and cheap to replace.

Hope it is the same for u.

 

Thanks for the post. I am curious how they determined it was the fuel pressure sensor. ???

 

Just purchased the vehicle used 4 days ago. Had no issues on the showroom floor other than it needed to be jump started as a result of sitting there and not being driven. No issues during 1k mile road trip, upon detailing and cleaning the vehicle, I tried to start it and it died off dipping under 1k rpms. Happened a second time yesterday, waiting a minute or so and it started without any issues. I have a feeling they were not using premium fuel as well as a mix of the change in seasons with regards to the fuel change. I will run this tank down, and fill again with premium, and determine whether I need to have the injectors cleaned.

 

...you didn't clean the engine bay via the hose did ya?

 

I think i am right in saying that there is a schrader valve on the fuel rail which can be used to measure fuel pressure

 

Oh God no, I actually learned about that with the '09 C63 AMG I used to have. This morning, super cool out and vehicle started with no issues. I love this car, but I have a feeling this is going to be an interesting experience.

 

I wanted to give everyone an update.
Since my last post on May 2012, my XJ been running and starting without any trouble. I am starting to think that the whole "Winter/Summer" gas theory may be the culprit ...?
I will keep everyone informed if my XJ starts exhibiting the same issues now that "Winter" gas season is upon us.

 

My car also stopped exhibitting this problem in late spring. I did put two cans of BG44 through the tank, but it was near the end of the winter blend season and I am not 100% sure if it was the BG product of the switch back to summer gas that fixed my issue. I will also be watching this close this winter and posting back here.

One thing I had to do on my old E-Class Mercedes was drop down to 89 octane to get the engine to run better in the cold. I may try that too this year. The $0.12 per gallon gas savings would be nice too.

 

Wow, timing is everything! I had just been researching the fuel changover thing since it's about that time.

Time for everyone to pay attention to the car; turns out Sept. 15th was the last day suppliers were required to maintain the summer blend, low vapor pressure gasoline. [that is, here in the States] Which means it will be going by the wayside, little by little over the coming weeks.

Here's a report covering the issue, fresh for this year.

Cheers,

 

A little further reading........ I knew I had this somewhere.

 

This does beg the obvious question though. Why did Jaguar not design an engine and system that can handle the gas that is available? If you are going to market your vehicle in a market as large as North America you should do whatever it takes to make sure the product works correctly with the fuel that is available. I may be wrong, but this seems like a bigger issue on Jaguars than other makes.

 

my 04 xjr had a broken fuel presure sensor, when replaced all problems were gone

 

Early cool morning in NC, warm motor, no issues began driving, added a little more acceleration than usual, check engine light came on. Arrived homw ran the code reader through the system recieved the following:

Code P0128
(Read as follows on the code reader)
MIL ON//NO MONITORS//0 INC//9 READY//MISFIRE//FUEL//COMP//CATALYST//EVAP//SEC AIR//02 SENSOR//02 HTR//EGR

Can anyone offer any advice?Going to shedule for Jaguar dealer service in Cary, NC this weekend.

Vehicle ran the rest of the drive home from work with no issues. Check engine light is still on.

 

P0128 alone (no other codes) on an 04 XJ is "Coolant thermostat range / performance", possible causes - "Contaminated coolant or Engine coolant thermostat failure"

This is also the explanation on an 04 XK and 04 Stype, as that's the newest MY that my DTC codes provide me on the JTIS disc. Good chance it pertains to a few years newer. I'd change the t-stat first with a thorough coolant flushing, then if it returns, the coolant sensor would be next.

 

CSEL was inspected and as you stated it confirmed the fault and the failure to engine coolant temp sensor:

Fix Requried a Thermostat, and they also replaced the seal. $65.85/Seal $12.57
Coolant Flush and addition of new Antifreeze. $79.55
Reprogram of Existing ECM using IDS/SDD $116.00

I also treated her to the fall special for $59.95 which covered:
Change Oil & Filter, check & top off Fluids, check and adjust Tire Pressure as well as a complimentary mulitpoint inspection which did not derive any futher issues.

Car is running smoothly now, I did not notice before but my cooling fan was not comming on after I stopped driving, when I arrived home, I heard it still spinning and realized that it had not been operating, a nice wash this morning and I love my XK even more

 

Not bad at all, glad it worked out for ya! Even though your XK is newer than the 2004 MY, you can still expect much of the DTCs in the JTIS to apply if you want to download it. Check the FAQ at the beginning of the xk8-xkr (x100) section for the link and how to install it onto your hard drive directly. Its invaluable.

 

Hi all,
I have a similar problem with my 2004 XJ8. When I parked my car and after ten minutes or so I want to start, the engine stalls. I really have to play with the throttle pedal and then the engine keeps running on idle. It runs very smooth on idle. But then the check engine light comes on. When I scan the OBD it shows the code P0105 MAP sensor Manifold Air Pressure Sensor as a stored code.
After a few drive cycles the check engine light goes away but the P0105 code remains as a stored code.
What I did so far:
I had a decarbonizing clean of the engine by Terra Clean
I replaced all the spark plugs with the correct ones
I did a brief vacuum air leak test with a propane torch hooked up to a hose and go around hoses and seal of the intake manifold when the engine is at idle. The engine didn't stall so I assume there is no vacuum leak.

Any suggestions more than welcome
Thanks