Hi

What causes a ef 6 cyl duel fuel to backfire and run rough in mornings when starting on lpg but a little better on petrol but otherwise start and run ok on lpg other times.

Done fuel filter

Leads are old and plugs would be too haven't done coil pack and looks like the original one don't think a new ones been put in

Would a crank angle sensor be possibillity and is it a unbolt and bolt new one straight back in wether it's side of engine or the little one on front of engine

Is the sensor on front of engine a simple unbolt and bolt straight back in


Any chance it could be fuel pump as it starts on petrol and switches to gas

Probably most of your problem

Would it be coil leads or plugs or a combo of all

Change you plugs and leads and see from there.

Do one step at a time.