Stuttering Range Rover 2000 4.6 on LPG

Hi guys and girls. Problem, lpg fitted 3 weeks ago, when running on gas, absoloutly perfect, super responsive and quick. On petrol, seems very lean and eventually when she gets going shes ok, but then under heavy acceleration she stutters and hold back under heavy acceleration at about 3000 rpm. Its a new romano adaptive lpg kit and I have had the petrol ecu reset to factory standard to try and solve this, it didnt. She seems to be running lean. Idea would be appreciated.

sounds like its not getting enough petrol to me

Hi Mate, yea thats what i thought, but i can't understand how, i've checked fuel pressure and flow to all injectors, cleaner the system with forte, still the same.