I was taking off from Albuquerque (ABQ) on a hot day. This airport is at about 5000 MSL. I selected TOGA thrust on the runway and subsequently increased my hardware throttle to full power. However, the A/T changed annunciation to THR HOLD without being at full thrust, but instead at about 86% N1. The engines never reached the max thrust rating and there was no assumed temp set either. Also, the takeoff page showed an N1 limit of 91%, which was never achieved. Is this a bug or am I doing something wrong? What is the real world procedure for taking off from high-alt airports in the 737-300?