peugeot 206 automatic

About 2 months ago I bought a petrol (Automatic gearbox) 206. the vehicle was 98000 km. I bought a lpg after I bought the vehicle. I had normal maintenance of the vehicle. Then, my vehicle started not to work at once in the morning, but it started to work at 5-6 times. But my work was not a problem until the evening. it works every time I run it, but it doesn't work again in the morning. I took it to the master. replaced the float in the benzim tank. the problem is not solved. does not work again in the morning. this time my master and the master who wore the LPG said; They said that your car may have been lying down for a long time, the gasoline in it may have worn out or even the octave might have flown. They said use it until you run out of gas, then buy gasoline again. I said OK. I started using my vehicle to finish the half tank gasoline. Gasoline had started to decline thoroughly, suddenly the engine malfunction lamp came on. I went for a few kilometers, I was stationed. It continued to burn again, at that time the gasoline burned in the sign that the fuel was over.

Now I'm going to run out of fuel and refuel. I wonder if anyone is having this and a similar problem, or are the masters telling me right?

Thank you from now.

this is the first time I've heard such a thing, but it sounded logical what the master said

I will rewrite after trying