Missing Problem of Honda Civic 2004
My car, Honda Civic 2004 Engine Type: D15Y3, has duel system of Fuel.
1: Conventional Petrol
2: CNG
There is no problem, when I drive with CNG. But when I use Petrol at normal running, suddenly the engine lost the power for about 2~3 second & after accelerating the engine by accelerator, it gets power back after a jerk. I have adjusted its spark plugs to its rated gape of 1 ~ 1.1mm & also cleaned it fuel filter too. But the problem is still there. This problem also hasn't appeared at high speed too. If I will accelerate the engine to 7000rpm for a couple of seconds then it disappeared too.

Secondly, after continues driving of 100 km/hr even for 10 minutes, when I idle/ stop the engine, the rpm of engine start fluctuated from 1200 to 1500rpm. This fluctuation of rpm became stopped after restarting of engine.

Pl. anyone has faced this problem & have solution pl. coordinate.