I have a Liana 06. The problem is that the car does not accelerate quickly. It feels heavy and at times just does not even if i floor the accelerator. Once the car gains speed it is very light and good to drive. The problem is on both CNG and petrol and increases when the AC is on. . have had it tuned from a number of places including Suzuki Central Rawalpindi and Enercon. Have had the plugs, plugs wires changed, tappets adjusted but to no avail. Need your advice or if someone could suggest a mechanic for Liana at Rawalpindi. thanks