Hi All,
Just for info.
I was have a huge problem trying to start my dedicated LPG BF RTV.
Anyway I ran across a bloke who does LPG work and he said that the battery was stuffed, or nearly so.
Apparently if the battery isn't 100% the gas injectors or something don't quite open all the way. (Can't remember exactly what he said) and the isn't enough gas to start the car.
Sure enough, new battery and it all went away.
So, if it doesn't start properly, check the battery.