Odd start up with 98 ron ulp

[NP99]

I have a dual fuel 4.5 that I run on LPG and 91 ron, I decided to use some 98 ron last week. Each start up from cold for the first few seconds it carried on like it was starving for fuel. Now back on 91 ron it doesn't happen, clean start and turns to LPG when warm enough!

Any thoughts guys?

[nissannewby]

Did it ping at all?

[NP99]

No mate, just starving of fuel and rough idle for a few seconds at each cold start up.

[Clunk]

Very odd indeed not heard of that before....... have you tried 95 ron? I use it all the time in my Q now runs so much better than when on 91 and no more pinging either but then again, I don't run gas.
Would it have something to do with how the gas/petrol mix is set up. Maybe 98 is too rich a fuel

[Robo]

I agree 91 mixture settings is proberly to rich for 98 ron.
and plug gap also smaller for lpg will prob cause petrol fouling of plugs.
also colder range plugs are generally use for lpg so this wont help either on petrol.