Discovery LPG

I assume we're talking about an engine under no load here? If it's under load then I ain't got a clue. If under no load, it's probably the lambda switching and the gas system hunting from rich to lean to rich to lean.... etc etc. This can be more pronounced on vehicles that have a long pipe run from the vapouriser to the mixer. Badger.

I had the same problem and the garage that fitterd it sorted it out no problem it was that the injectors where to big .Now that thay have been changed it runs fine in fact runs bstter on lpg than on petrol hope this helps