Hi, as stated in the title my car would not rev over 3K when driving, and if I prodded the accelerator at any speed the car would 'lurch and jerk' as if suffering from fuel starvation.

When I searched the forum I found there were a couple of threads on this problem but none that had a solution.

So I thought if it feels like fuel starvation then it might be, so I should replace the fuel filter.
This made no difference, so I went to google, and found someone with an XKR who had a solution!

Dan Pechonis
dpechonis@austin.rr.com
Forum name: MrTexasDan

He had uploaded a wonderful PDF that showed 3 tasks to perform.
Clean the MAF, clean the throttle body and finally clean out the part load breather.
These tasks only took him about an hour, but I only had 10 minutes free today, so I just tried the quickest and easiest job to do now, and then do the slightly more involved jobs tomorrow.

So I took the MAF out and cleaned it, leaving the other steps till tomorrow when I have more time.

I will do the others tomorrow, but the MAF clean FIXED the problem!

I could not believe it I only bought this car a month ago, and it always had the problem.
The performance is transformed (of course it is, I have another 3000 revs to play with now!)

I am attaching the PDF, but a very happy Chappy now.

Peter

 

I am fairly sure that your Jag is in limited performance mode when it limits the revs to 3000 rpm. Also called limp mode.
The possible reasons for being in limp mode are plentiful. Sure, if you are extremely lucky, one of the "fixing methods" your are proposing might be the right one, if you are extremely lucky...
But I would actually have expected, that you also get the message "limited performance" in you display and that the CEL (check engine light) is on.

The thing that you need to do is check the failure codes in your Jag with an OBDII code reader.
I have an expensive but rubbish one, and just found the time to test my other 2 very cheap ones, which do the trick just the same. I just wrote about my experiences with the new scanners here, in the third post of this thread:
https://www.jaguarforums.com/forum/s...-start-286065/

The scanner will hopefully tell you what to fix.
I bought my X308 in limp mode, and the scanner told me exactly what it was: In my case the knock sensor needed to be replaced.
In case that is your problem as well: The knock sensor can be found cheaply on Aliexpress. I bought that and no more problems with limp mode ever since.

 

No check engine light, messages on the display, andI had no codes.
I use an expensive Icarsoft V3.0 jaguar/landrover scanner so if there were any codes to be had I am sure it would have shown them.

The performance was very acceptable and be of the way I drive, I didn’t notice any problem on the test drive, or indeed on the drive home. It only showed up when I was cruising at 70 on the motorway and went to overtake. Car just started lurching until I backed the throttle off. Because I normally only drive using the first 2” of peddle travel I had no problem, but pulling away fast from a junction and the lurching would start.

As I said, NO codes, NO messages.

Problem went away after cleaning the MAF.

I could/should have read the live feed before cleaning, but didn’t so can’t say what changed, but it’s working now so happy happy person

Peter

 

So it works after cleaning the MAF... - that was not clear in your initial post. OK, so all good.