My uno was sat on a drive unmoved for 3 years. When I came to shift it it started fine. Went to fuel it up at the petrol station and just as it got out it cut out and wouldnt start. I later found out that a part of the fuel line had rotted so little bits of petrol was going through but not enough to actually drive it far. It was ticking over and starting but cutting out as soon as you tried to drive off. Maybe its something like that.