Car: Honda city
Fuel type: Petrol & CNG
Overall Engine condition: Total Genuine, no work done till now except CNG installed for last 7k
Problem: Very light jerks on petrol only observable more on low rpms... On CNG its very smooth.
My Observation: i felt that before this problem when switch on car ignition switch then i sound of fuel pump was observed which stop after 2-3 sec,,,, but now a days there is no such sound.
Plugs are fine, air filter, oil filter, engine oil replaced on time.
What may be the problem???