I have Landi Renzo CNG kit installed in my Carby car. It sometimes gives problem when converting from Petrol to CNG and the issue is that on conversion from petrol to CNG, the supply of petrol does not discontinue and petrol keeps on flowing to carburetor. This issue happen sometimes (not all the time). In this situation, it convert back to Petrol two or three times (through the CNG/Pertol Switch installed on the dash board with CNG indicator)and then the supply of petrol discontinue and car convert to CNG. Please help how to resolve this issue. I want to avoid going to the so called CNG mechanics for this issue.