vincent17

hi, i'm abit of novice to the bmw engines for the moment, I have fittted in a new trans to my 25i and have done it pretty much without a book so its not exactly bang on but we have a runner, with a little problem that didnt exist beforec the trans was fitted. The motor is surging off idle till about 1500 - 2000 rpms I have sort of narrowed it down to the vacume set up on the motor not perhapes operating correctly. Does anyone know what is causing this to happen. Thanks Vince