i bought liana a month ago, was missing and jerking on cng, then it got worse and refused to run on cng, i took it to suzuki 3 S, they resolved the issue, jerking and missing was one problem and its refusal to run on cng was a separate problem, they corrected some wiring issues, some were under the hood and some under the dash board on second seater side, it took only an hour or so and its running perfect now, alhamdulillah, so suggestion is to first get it checked from Suzuki 3 S, if they cant do it then move to some freelance mechanic