Spluttering on gas but fine on petrol

[Zhaan]

We have recently bought a Vauxhall Frontera 2 litre truck with an LPG gas conversion.

We took it out tonight and for some reason it wont get out of second gear and the engine management light comes on. It wont tick over, it just cuts out. When it does drive it splutters and holds back, no power.

When we switch back to petrol, it runs smoothly.

We are thinking of taking it to the local LPG mechanic and asking for a service.

Apparently the truck had been stationery for a year, does gas have a shelf life?

[mak-uk]

When sitting around a while, it's worth getting it serviced on both the petrol and LPG.