2006 Hyundai Terracan no accelleration

Hi we had just finished a trip of 3300 kms towing our caravan, when just around the corner from home we experienced a loss of accelleration. We stopped the car restarted changed gear but to no avail. The motor was still running normally,After about 5 tries the accellarator finally kicked in only to stop when we turned into our street. We called the nrma to be told he couldnt find a problem. Since then we have had no problems but it is really puzzeling as we are wanting to take the van away again. My brother suggested that the computer would log what the problem was but he is not sure how long the computer would keep this information.
Any clues pls. It is a 3.2ltr turbo diesel and we have had no other issues with it before.
Thanks Owen