people, for your problem, there is an official solution. i had same fuel consumption problem too, that my car runs 90sec on petrol on start up. but now with the same switch, with no hardware/wire changed etc, my car converts in 7 sec to CNG. All this done by just update/amendments in software/ECU of car by computer. and it was done by SUZUKI DANISH MOTORS. i went for just engine tuning of my car, shared my problem with them, and they solved it by just attaching a laptop and updating software. and now am happy with it with no problems since 8 months. This means that all the official suzuki workshops have ability to do this job. hope this will help your problem. thanks