All fixed
Spent some time under the bonnet checking all the wires and connectors and it was a broken wire that was going into the Reducer/ Vaporiser. It looks like it linked to a solenoid hence it was not getting the volts to kick into action.
Fixed for now and a new connector ordered so I can repair it properly.
In regard to the car on LPG its OK for long journeys. I get about 200 miles to a tank of LPG that costs £35 or so. Yes its a little down on power and can be sluggish to respond to the throttle but if you are having a proper drive I just switch it back to petrol as needed.
Its a good addition to the car, keeps the costs down on longer journeys and allows me to say I drive a Hyrbid