Almost a week ago, I got my hands on the Cuore CX CNG I had booked earlier. It came 43km driven. On the first day of getting the car, I drove what I remember to be around 20km or so on CNG. I should mention that the car came with an empty petrol tank, but the CNG tank half full (from which I presume that the initial 43km were done on CNG). In the even of the first day, when I took out the car after a brief rest following a long drive, I noticed that the engine in the car was hiccuping on second and third gears. It would feel as if the car were throwing up -- almost shaking. The next day when I took the car out for a short drive, I felt the same hiccups again, which deteriorated the driving experience completely. I figured it could be due to running the airco on CNG, but having turned off the airco, I could feel the same hiccups on second and third gear. The engine wouldn't hiccup all the time, but most of the time.
I immediately took the car into the authorised service centre where they serviced it to get rid of the poor pickup problem. After the service, I did not feel hiccups.
However, I have noticed that if I shift into the fourth gear, the car would start shaking severely, with the engine coughing up. It feels as if the CNG supply gets restricted. At first I thought that keeping the foot on the pedal would gradually get rid of the hiccup in the fourth gear, but the car would go on shaking and shaking until I would downshift.
I then switched off the fuel supply to petrol to narrow down the problem to carburetor. But to my surprise, the car picked up surprisingly well on any all the gears I tried it on. I took the car well into the fourth gear, pushed it hard, slowed down, pushed hard again, while staying on the fourth gear, but I felt no problems.
However, on CNG, the car starts shaking. I am not sure what the problem really is. I will take the car again into service centre. It is a brand new year (with Tracker installed, I may say, but I don't expect Tracker to have caused this problem).
Any clues and suggestions would be appreciated. It's a brand new car.