4.6 odd stating when medium warm

Morning all interesting problem with my v8 set up is petrol and prinz gas system.
Starts on petrol and runs a bit odd used to be very sweet and if left on petrol it runs ok a bit of rev variation at constant throttle if switched to gas it is a little smoother However if switched off takes for ever to start in either petrol or gas mode.So reset adaptions the lambdas are giving a nice sine curve maff is showing 22kg at idle air intake is showing about 25oC above ambient coolant showing 80 oC
So question where do I go next I have another p38 so can swap sensors etc jut not sure what next step should be
Any help much appreciated and have lynx diagnostics so if anyone needs a hook up I am near heathrow glad to help a fellow lunatic

Have a look around the idle air control valve, whichever version you have, and the inlet side in general.

Otherwise ignition coil or flywheel sensor.

Peter

Will do suspect an air issue thanks for pointers