[SUB]History: I have a Honda Civic 2005, the odo is around 80,000 KM. I got CNG installed at around 12000KMs. In the previous year, the engine check light came up twice but i never get the OBD scanned regarding why it came. However it was quite some time ago and the problem i am about to discuss has started recently.
Problem: Kindly note It only happens when i am running on petrol, no such issue when the car is on CNG. Hard to explain but here is the scenario:
My car is in first gear, the accelerator is pressed a little, just enough so that it does not go above 3k rpm, the car starts moving and randomly while accelerating, it gives a really hard jerk and then within half a second goes back to normal.
Second situation(happens in all the gears but jerk is hard on low gears) is that: The car is moving at a constant speed, i see the traffic ahead slowing down so i take my foot off the accelerator, and the car starts slowing down. After a while the traffic ahead starts to move again so i slowly press the accelerator but the car does not accelerate, instead it starts slowing down even at higher rate (as if brake is pressed) until i press the accelerator more and then at one point it gives a jerk and starts accelerating like normal
What sort of behavior is this? I am going to honda dealership this monday for power steering bleed and oil change so i want this thing to be fixed as well.
It will be better if great minds like sir @Xulfiqar can shed some light on this problem.[/SUB]
Edit: throttle body has been serviced twice in 80k km i dont think it might be the cause because on CNG its perfect.
Also there is some tak tak tak sound when engine is running idle (whether on petrol or CNG)
Also the clutch bearings need changing but i dont have budget for that right now, i still doubt its not the cause because its fine on CNG.