Subject: trany prob.94 3000gt automatic
Question:

When car is cold,car runs great for about 5 or 10 blocks,then begins to slip badly.when car returns to being cold,it will run good, then the same slipping problems happen when it is hot.

Answer: Larry,
You may have a low fluid level or particularly dirty fluid. There may even be a clog in the transmission cooler and the fluid is overheating. Have your mechanic inspect the fluid and get a flush and fill of transmission fluid; which should include a transmission filter change.
Good luck!