Thank you for the suggestion. I read that thread.....long! problem for me is I have no pining and his problem was pinging. Plus, when I pulled my plugs they were all clean, no carbon buildup.

I've ordered a new few fuel filter and will pop that on. If that does not fix it, which I don't think it will fix it, I'll have to go in for a computer read I think

 

I have a howling sound from the rear, either carrier axle bearings and or wheels bearings, I have had TC flash over hard bumps, making me think it's a bearing. I have a MAF code that comes on ONLY when it is HOT outside and I too am having nearly the same shifting issues.

 

Cambo is very in tune with what the car is doing, also he got to it early
Think of it this way it like a banana in the tailpipe!!!

When he talks about carbon buildup he is talking on the underside of the valves, as observed with an inspection camera

Bottom line get the codes done but bear in mind there is no code for a bloked cat only one that is not working.
A blocked or partially blocked one will still function emissions wise but will not flow.
This condition will not produce a cat related code

Cheers
34by151

 

Does the problem get better in second and third gear? I have had an almost identical problem on two cars, a BMW and my 2004 XJR. Both were caused by the same thing, a broken motor mount. The engine would torque up just enough to open a gap somewhere after the mass airflow sensor. In the BMW it was a split in the intake hose, and in the Jag it pulled the hose off the air box. By second or third gear there was not enough torque to open up the gap. When the gap was open, the air was not going through the mass airflow sensor, so the ECM cut the fuel. The engine would drop back down, the gap would close and the computer would restore the fuel, and the torque would promptly open the gap again, and repeat. It felt like stepping on the throttle, releasing, stepping on the throttle, over and over.

In the XJR the problem is an aftermarket intake pipe that's a little short, although there was no problem before the mount broke. Make sure there are no leaks between the MAF and the manifold.

 

Do you have any access to live data when this surge is happening? What are the fuel trims, MAF, and fuel pressure doing?

 

Yes, any gear.

 

No. How do I get access to live data?

 

OBD tool such as elm327

 

Thanks! I did not know these were out there. Which APP are you using with it?
How does this look?

 

People use various such a torque.

There are hundreds or thousands of supposedly-the-same-but-not devices but most seem to work OK. You can still be unlucky.

 

Well. I figured it out. What it boils down to is a Jaguar design defect--a defect that can lead to premature wear of your engine and even destruction of the engine!

Really DUMB what Jaguar did! The plastic intake that feeds the plenum is CRAP! First, there is a cylindrical plastic tube that is attached to this plastic tubing by adhesive. In my case, the adhesive had dried and gone brittle with age so much of it was gone! This causes a fluctuating air leak. Not only that, but guess where that decomposing adhesive goes? Sucked into the engine! Great for the rings. Not!

The hose that comes from the air flow meter attaches to the plastic by, you guessed it, adhesive! That too had gone bad so that the hose LOOKED like it was attached to the plastic but when moved I could see it wasn't!

Suspecting this was the problem, I took the plastic component off the car and as best I could cleaned off all the old adhesive. I've been attached everything with a very liberal amounts of duct tape making sure to use very long strips so that it would not be possible to be sucked into the intake. I reassembled everything and test drove the car. Problem solved! All due to a design defect any take system from Jaguar. Now I need to replace it with something better. Some form of a direct Cold air intake tubing to bypass that crappy design.

 

I wouldn't say that solved to whole problem. It is ONE of the problems that can cause the trouble, as I pointed out above.