Hey guys,

Hopefully someone can help me out with this as I am clueless. For the longest time now, my 04 x type has had an issue with what seems to be a fuel related problem. Basically, it looses power after a bit of driving, like something was clogged some where. Initially, no codes showed up and no CEL came on. Over the summer I had a code come on which read "Fuel rail pressure too low." I can't quite remember the number. Since then that has gone away. The car actually began driving okay as the weather got colder. Recently, that hesitation/lack of power, has been more of a problem. As of Tuesday Dec. 10, I had a p0171 "System too lean Bank 1" and a p2098 "post catalyst fuel trim system too lean bank 2" code come up. I checked and cleaned the MAF sensor, which did nothing. I erased the codes and they have yet to come back, but the same problem still persists. What could it possibly be?

 

What it sounds like is your fuel pump may be going out. Try this. Go to an autozone and get a fuel pressure tester.(free loner tools) There is a cap that looks like a air stem valve on the rail located on the passenger side of the intake.(rail is usually chrome). With the car off plug it in turn the car on and check to see what pressure is at. It should be 40 to 55psi. Then have someone give it gas and see what it does. Report back and we can go from there.


Thanks and Good Luck,
The Dr!

 

So we have a pressure kit, but cannot find out where to hook it up. All I can see is the valves for the AC line. I see the fuel rail, but not sure where to hook the gauge up.

 

On the chrome fuel rail there is a valve that looks like a tire valve. Hook it there.

 

I still cannot locate any valve whatsoever to test the fuel. I read somewhere that it was taken out in the 04 models. The problem still persists and my error codes are still the same. p0171 and p0174-running lean on both banks. Also it says fuel pressure sensor circuit high input.

 

Those codes are for vacuum leaks. Those are probably the most common codes seen on here. Do a search here and you will find all kinds of information on them. Big three are IMT O rings, brake booster valve, and the PCV hose. If your car still has a smooth one chances are that hose has a split in it on the underside. The newer ones are ribbed and much stronger. All three of those are easy to fix and pretty cheap. Good luck.

 

Here is the extract from the Jaguar DTC List for P0171 and P0174. See the right hand column for 'Possible Causes':


(click on the image to enlarge it)


You will see under 'Default Actions' that maximum engine speed is reduced when these fault codes are logged which explains the loss of power.

P2098 does not appear in the Jaguar list.

The random occurrence of the issue and improvement in colder temperatures points to a sensor problem more than a fueling issue.

Troubleshooting this is going to require some sophisticated testing and, as others have suggested, a professional diagnostic could be the lower cost option.

Graham

 

thank you very much. I don't have a lot of resources available to me as far as professional testing and diagnostics, but will look into these issues and see what I can come up with.

 

First thing I'd do knowing you had a low fuel pressure warning at some time in the past is to put a new fuel filter in it. Only cost's $15 and takes less than 10 minutes to change. When I replaced mine, I couldn't believe the amount of old dirt/crud that came out of the old filter.

 

Although it has been some time (almost a year), I did replace the fuel filter and the problem still resided with the car