I AND THE LOCAL BMW CENTER COULD NOT FIND THE PROBLEM? IS UR CHECK ENGINE ON WHILE THE JERKING IS OCCURRING? MINE IS? IT ALSO JERKS REAL HARD WHILE DRIVING NO MATTER WHAT THROTAL I AM AT?? I THINK IT MIGHT BE A ELEC. CUT OFF BEING INITATED OFF AND ON? I SWITCHED MY ECU AND NO CHANGE? PLEASE EMAIL ME PRIVTLY AND WE CAN CHECK SOME OTHER THINGS! ADAM P..