So today, I drove the car about ten miles, shut it off for a few hours and when I started it back up, it didn't run so good. By the time I got home, it didn't run right at all. The dash said restricted performance. I have never put new plugs in it so I thought I was due. Well, that didn't change anything. I"got a real good reader and it tells me misfire on 5678.. I can clear it for about two minutes and it comes back to restricted.... I'm about to go nuts.... PLEASE Help....It's a 2000 XJ8 VP
Thanks

 

maybe it jumped time

did you change the secondary cam chain tensioners?

 

How many kilometres/miles are on the vehicle?

Has any recent work been done to the engine?

Does the engine have the latest versions of the primary and secondary timing chains, guides and tensioners? If you're not sure, remove the Bank2 cam cover and inspect the cam timing by rotating the engine by hand in a clock direction only when view from the front of the vehicle using the 24mm crankshaft bolt to see if the camshaft 'flat' areas are in alignment.

If not, the exhaust camshaft is out of time and can bend the valves if the timing is off by more than two gear teeth.

 

No, I haven't. It was running fine and by the time I got home, a four mile trip, it was running rough. That's when I changed the plugs etc. I just took apart the mas and cleaned it and still no change. It wasn't really dirty..I'm getting despite...When I step on it a little, it runs great...