Dude, I'm having the same problem as you... My car will idle fine but once I accelerate beyond 50km/h the engine surges and jerks a lot. I've even had the car shut down on me once before at a red light, I thought it was a battery problem since I was jammin' to the tunes too loud but my old man brought up the fact that there could be some debris clogging the fuel filter. We had recently replaced the fuel lines coming out of the tank. I'm home for the weekend so hopefully I'll be able to solve this problem.