I showed it to a Toyota dealership today, a guy there said that the coil is short and needs replacement. But they did not have the original one cus they dont keep cng kit spares ( however they do sell factory fitted CNG cars )
Nevertheless I showed it to another CNG mechanic and he tested by removing the switch and shorting two wires in the CNG switch connector. After this the car started normally on CNG and there was no TIK TIK sound...
he said that the switch is faulty Not the coil.
I am now going to replace the switch and see if it actually solves the problem..
Any idea if the coil could be faulty too??? Anything else that could help???