Idling controllers and strange driving behaviour

Hello, with my Omega A 2.0i with LPG the idle control is complete because the speed varies greatly when it is connected. To this end the MKL lights up and the readout only indicates that the idle control is just finished. For me as a layman the thing is a real thriller because I just can’t explain a few things: If the controller is always closed the car must react similarly in similar situations – but it doesn’t: Usually the car only works at the beginning If you walk off the gas, sometimes but also if I let it roll down a mountain in the middle of the highway in a warm state without a gear (which I avoid from now on). If I drive with super gasoline the car goes out without gear and gas even if it has reached almost normal operating temperature, however, if I drive with LPG or Superplus this happens only the first meters. If the speed is low (about 300 revolutions) and the car slips in the stand and I get a little gas g ebe often goes out – according to my logic the opposite must happen. (If I give more gas the engine stays on). Is the story also mysterioes for you or is it just my lack of expertise? How can I fix the problem with the idle controller? Greetings and thanks for any help Desperado