Not wasting any time with my first technical question - I'm wondering if anyone may be able to help me with this problem with my Daimler XJ40.

I made the mistake of leaving her with a friend for about a year (storage problems!) and she did get driven fairly regularly but since I got her back she's been very hesitant when I ease off the throttle at motorway speeds. Sometimes it's only a vague hesitancy but at others it's very noticable indeed. It's as if the car's lurching backwards.

I thought it was a faulty air-flow meter but a replacement has not fixed the problem.

Any ideas? - Cheers!