Misfire ???

[Mechcanico Lee]

Couple of thoughts ...on some engine missfire detection only works up to about 1000 /1200 rpm when stationary any higher than this it switches off

It may detect missfire whilst driving as road speed re establishes the function .

The switching injectors over to petrol one of a time is a strange one , does the gas system have a single map sensor or twin ?

Try in plugging both lamda sensors whilst on gas to see if trim adaptations is affecting time open duration on that number 8 .

Does the gas have one feed to the gas rail or twin , is gas pressure ok , are gas filter units ok .

If it has twin gas regulators you could try swapping supply pipes over on gas rail to see if it transfers to other bank , obviously if it's only one supply and regulator type forget all this .

Whose system is the gas .......Romano ....Bi gas ??