Hi

I've read through similar threads, still not sure what the problem is.
I've had the 97 xj6l 4.0 for a year without any problem. Suddenly the idle got bad when the car was in park. The gas tank was almost empty, so I am suspecting a problem with the gas delivery?
On the other hand, from the exhaust it souds more like a ignition problem?
See video:
https://vimeo.com/126835516

The car runs "ok" in speed, but the idle is uneven and bad, there is also a lot of vibration from the engine.

I have tried to disconnect one coil at the time, but could't point out if one of them is bad.
Could changing the gas filter sort out the problem?