I have recently overhauled my Santro plus 2001 engine with the best quality parts available in the market. The reason for overhaul was due to the weak piston and rings condition, oil was rigging out of the ring seal so it was necessary to do the overhaul. I spend 30k + on the overhaul and overhauling was done by a Santro expert mechanic. Before the overhaul the car was running fine on petrol and it could easily go above 120km/h with AC, but on CNG it was having Santro's generic backfire problem.
Now after completing the initial running of 3000 km on Petrol. Whenever I try to take the car above 100 km/h it just stays there and nothing happens. Initially i thought the problem is with the CNG settings, but the problem is same with the petrol also. Accerelation is fine, but whenever the speedometer touches 95km/h to 100km/h, the car does not take more speed, no matter how hard you try. I have also checked the fuel pump, plugs, cables and done the tapet cover adjustment but the problem is still there. Kindly tell me what is the problem and how to resolve it ? My mechanic has even replaced the ECU with another Santro's ECU but the problem couldnt be resolved. Please help me.