I'm still having issues with the Jag it's still jerking and bucking upon acceleration. I still have not been able to get a code the light only stay on briefly at that time. The care runs OK at an idle except for an occasional shake of the engine. When I accelerate it misses more, but only if I accelerate above 1.5 to 2000 rpms on the tack. That is until I get to about 40 to 45 mph... then the check engine light will come on until I get back down below 40.????

 

My X-Type

 

Not an expert but it's a good idea to retrieve the codes thus it would be easier to diagnose what's what .
Hey, your ride sweet

 

I had a very similar problem -here is what I did: - I went to O’Reilly’s Auto, and they pulled the codes- I would get Cyl # 1 misfire. I did two things- first I replaced the Plenum gaskets (both upper and lower) - that helped, but then it changed to jerking at 40-45 MPH only – instead of up to 45 MPH – and then No Check engine light unless I stomped on the gas. Went back to O’Reilly’s, pulled codes again, and same thing Cyl 1, misfire - Next I took out the E3 Spark plugs (only about 8 months old) - and replaced them with Bosch Double Platinum. Bingo - fixed the problem, runs like a new kitten again. In the mean time, I called the Jaguar dealership in Portland, who told me that he has seen a few issues where anything above the double platinum (to include the Platinum +4) was causing misfires and poor performance on this engine. ( - on that note, I do know people that have had NO problem with the E3 plugs - so it might be hit n miss - if they will work for you).
I would suggest you try changing your plenum gaskets and your spark plugs- total cost was about $50 here in Alaska - and there is a great tutorial on how to replace them here on the forums as well. It takes a couple hours, but it was worth it for me.

 

Been to two different auto parts places and used two different scan machines and still unable to retrieve a code from computer i started have this problem months ago and the first thing i did was replace PVC, brake booster vacuums and clean and check MAFS sensors replace fuel filter and IMT rings. Also installed Bosch Double Platinum spark plugs so know you recommend i should replace the and lower gaskets? - i did the upper gaskets when i did the spark plugs.

 

No guarantees but I was about to pull my hair out trying to figure it out too - I had the problem for about 4-5 months before I was able to fix it. I did try everything you mentioned as well first- fuel filter, Mass Air Flow, etc. It’s only a couple more bolts to get to lower gaskets. Good Luck - Let us know

 

Check the map sensor I was having the same problems I cleaned it it did perfect for a bit then started again I did this 3 times mine is a bad map sensor

 

Lol, 8 year old thread