Hi. What sound decoder is it - ESU LokSound (Murphy Models supplied) or Zimo? Check CV5 is not set at too low a value (i.e. Max Voltage values between 0 and 255). Try setting it to 255 on your DCC test track, and see if that makes any difference by testing on your main track. Also check what CV3 and CV4 are set to (Acceleration and deceleration), just in case the acceleration delay was set too high. PS: Make a note of any CV values before you change them in case you need to revert back. PS2: Best to post this in 'Q&A' forum to get more visibility and more replies.