I am a wrangler newbie. I just bought a 2005 TJ Sport 6M with 52000KM on it. I have replaced the greasy dark air filter with a Fram air filter, and put in 6 Champion 4412 spark plugs.
But a problem has happened several time recently. When I shift into the 2nd gear and begin to accelerate, the car begin to jerk heavily, put on more gas to bring up rpm to 2000+ rpm just made it worse. It feels like someone steps on break repeatedly, or the engine output slipped. When I shift to the 3rd gear, the jerk disappeared. This has happened in the first and third gear once or twice too. It doesn't happen regularly, but most time during start up after driving for a while.
Has anyone had the similar experince before? Please help. Thanks in advance.