Sounds to me like the low speed needle valve is off a bit. You can check this before you even start to taxi by idlying the engine for say 30 seconds and then hit the throttle. If it starts to smoke and sputter in stead of speeding up, the low speed valve is set too rich. If it dies right away, its too lean. Make small adjustments, 1/8 of a turn at a time and get smaller as you get close. Once you have it, you should be able to idle for a full minute, or more, hit the throttle and have instant high speed throttle repose.