Peugeot 605 V6 with LPG car gas

Hello, I had my V6 (Bj 2000/140KW) rebuilt and now drive with car gas (LPG). When refuelling, the number of liters is now turning faster than the Euro number: that’s wonderful. In gas operation itself, the engine also ventilates satisfactorily. But of course, the engine always starts in petrol operation – and there are problems: it jerks strongly and takes on bad gas. It runs far too fat. After switching to gas operation after approx.30 … 60 sec everything is then OK again. There is no mistake in this. I have now made a reset of the motor field several times ((+, – cable together). So the engine runs again wonderfully in petrol operation. After switching to gas operation and then again to petrol operation, the old problem is there again: that is, the engine gets wrong information somewhere. But where???? I outsmarted it a bit and paralyzed the heater of the Lambda probe (secure #11). It takes a little longer then until it takes him a little longer. of course, the on-board computer also spins: it calculates a consumption and counts down the digital display of the petrol residual volume and the liters become less and less – although it almost does not consume gasoline. When filling e.g. 5l petrol there are again many liters in the display. But I don’t think that this is the problem. So, who tells the adaptive engine control unit that it should grease??? I’m curious about your factual/technical answer. eotwerkstatt have so far no answer. Best regards paroni73