i have a santo model 2008 which is done approx 36500km. till yesterday the car was running fine.i drive the car on petrol once a week all day. it used to start on petrol and then automatically convert to cng. but now its not working on petrol anymore. i have to directly start the car on cng. the car on petrol keeps on choking and feels like as if there is not enough fuel comming in it also when on petrol the exaust also smells as if its not burning the fuel properly, while on cng the car is running perfect. my car used to take water from cylincer on both petrol and cng. need help on how to fix the petrol problem.