I've owned this car going on two years, and have had very few problems (thank you, Jaguar gods). Soon after I purchased it, I floored the throttle from idle, the car hesitated, then went into restricted mode due to Lean Bank A and B codes. I reset the system and have had no problems until yesterday. Floored the throttle ( I was in "Normal", not "Sport" mode), the car hesitated briefly and the check engine light came on with the codes showing lean conditions in both banks, but no restricted performance. I also get some surging on WOT in either mode, but acceleration is generally strong up to the red line in all gears. The fuel filter was replaced approximately 6,000 miles ago and fuel trims for both banks are near zero at idle. Car runs near perfectly otherwise. I'm wondering if the problem is associated with:

1. The transmission being in too high a gear when the throttle is floored (Normal mode).

2. A weakening fuel pump

3. A throttle body problem

I've not checked the fuel rail pressure (not sure what it should be; 35 psi?).

Thanks in advance for any help.

Max

 

From the JTIS for your MY
Disconnect and plug the vacuum hose from the pressure regulator.
Start the engine and record the fuel pressure reading.
As a guide, the fuel pressure should be approximately 3.0 bar (44.1 psi) with the regulator disconnected.
With the engine still running, reconnect the vacuum hose to the pressure regulator and record the reading.The pressure should drop to approximately 2.6 bar (38 psi) when the vacuum hose is reconnected.
Switch off the engine.

You are getting too much air at WOT which means your vacuum pressure is pretty high, you may have a small air leak which only manifests itself under these conditions. May want to check air box and associated connections to TB (which may also inc TB gasket)

Check the pressure as above, it could be pump can no longer maintain it's maximum demand under sustained WOT. or it could be the regulator itself.

 

Thanks so much; just the troubleshooting process I was looking for.

Max

 

I too was getting those codes intermittently, and then more and more and more... when I FINALLY dug into the issue and started looking for an air leak I noticed that the bottom of the bellows on my air intake tube had dried out and cracked and were letting in too much air (hence the LEAN codes for BOTH sides)... here is my original post HERE.

Worth giving it a quick look... maybe you'll get lucky like I did.

 

Would that it were that easy. I changed out the plastic air intake tube for a solid aluminum one from MINA Gallery several months ago, so that likely isn't the problem. This has happened twice in two years, so its more annoying than chronic. I'm going to check out Jamdmyers suggestion regard ing the fuel pressure regulator and fuel pump pressure. The strange thing is that most of the time when I floor it in Sport mode, it takes off and howls up the road right up to the red line in each gear. As I said, very intermittent.......

Max

 

I have the same MY car and had a similar problem a few years ago. The culprit was the MAF sensor. It is a lifed item. Easy to change and problem gone.

 

Thanks, Hare. I have no way of testing it but, depending on how expensive it is, it might be something worth replacing as a precaution. I'll check in the stickies and see if someone found a non-OEM unit that might work. If not, guess I'll just bite the bullet.

 

What were the codes you got and what modifications have you made. Attached is a list of the Jaguar codes and what to look into.

Link http://jagrepair.com/images/AutoRepa...7_ECM_2000.pdf