Well it is hard to say but I can tell you this. Your Acura's timing belt is due every 6 years/90,000 miles. So it should have 2 timing belt replacements by now, but that is not guarantee that it has ever been replaced. One thing to do would to look at the condition of the drive belts which are visible on the outside of the engine. If they have cracks in them then that may be a clue as to whether the timing belt has been replaced or not. Most of the time the drive belts are replaced when replacing the timing belt as they need to be removed to get to the timing belt.If the drive belts are new looking then that can be misleading because they may have been replaced independently but if they are old and worn than you have some real good information on whether the timing belt has been changed or not, you know what I mean?