Shaking between 2 thousand and 3 thousand cycles

Friends, respect. My car has shaking between 2000 and 3000 rpm. What is the solution. I changed the spark plugs and the gas adjustment was made 2 times. I had the cylinder head gasket replaced, the valve adjustment was made in the gasket process. It doesn't do it all the time. There is no problem with my take offs. If I go on top of it, this time it throws itself into gasoline because it doesn't eat gas. What is the way I will follow on the subject? They said it's a coil, but I think it would do it at high speed if it was a coil. I'm waiting for your help.

First of all, use gasoline for a while if there are no same complaints. problem possibly parts to be checked in the lpg system lpg injectors - lpg brain (regulator)