I took the car to CNG mechanic, the car was on CNG. He tried to convert it on petrol but the switch went mad again so he said that the switch is faulty and it needs to be replaced. The price of touch type switch is Rs 1200 for a desi one and Rs 2400 for genuine.
However my mechanic asked me to go for second opinion. He asked me to visit Chaudhry CNG opposite RMC. One thing I noticed that if the switch is in mad state and you leave it untouched for 10,15 minutes, then after that the car can be started on CNG without any issue.
I went to the above mentioned CNG station and explained him the whole thing and he said that the problem is with fuel pump, not the CNG switch. He said that CNG switch has four stages.
1) When on petrol. (Orange light is ON)
2) Converting from petrol to CNG. (No light is ON, which means that both the fuels are stopped)
3) When on CNG (Yellow light is ON, along with other lights which represent amount of CNG present in cylinder)
4) Converting from CNG to petrol. (2 lights are ON, orange for petrol and yellow for CNG)
So he told me that in fourth step, the car is not in neutral stage, infact both the fuels are open (as represented by their respective lights).
As soon as petrol reaches the combustion chamber, you feel a jerk and that is the time when you press the button again to cut the CNG supply. So in my case petrol was not reaching the combustion chamber and that is why the car kept on driving with both the orange and yellow light because it was CNG which kept the engine running.
Electronic pump wire was loose. He tightened it and the car start doing the conversions correctly. Thanks God I didn't have to spend that much amount on switch.
