Thank you very much ekdrifter, man!! I like your style of explaining things. Sure I am new to cars but I have passion to learn engineering stuff :). I disassembled and then assembled the mechanical of my Panasonic VCR 7 years ago after downloading its diagram from net :D...(I just luv DIY).
I was just afraid to go to mechanic as someone told me that if you got patrol adjusted then they will mess cng settings and mileage will be affected.
There is another issue which I would like to discuss: My car starts after 4-5 self tries (on CNG. not using patrol as it needs adjustment). When it starts, it gives blueish smoke with smell for a minute and then smoke vanishes and everything is fine. Can you please tell me why this smoke is coming at startup and could it be fixed with tune up of the car from good computerized tune up?
Thanks again !