Idling issue duel fuel TB42e

[Pete49]

I'm getting balder by the day. I set the timing on the wagon idling on 750-800 rpm then when I restart it it goes and idles at 1400 rpm or more. I replaced the head gasket but didn't alter anything else. No vacuum leaks, all vacuum hoses on. Its running on gas as for some reason when I switch to petrol it cuts out, no fuel getting there. It wasn't a problem before I pulled the head and all wires appear to be connected. Never had a efi Patrol before so all new to me. Is there an Idle adjustment screw on this motor? I have the gas timed at about 12 degrees BTC as any higher and idle lifts to much. Any help would be much appreciated especially with pictures
Pete

[Pete49]

bump
Anyone?