If your Nissan stops accelerating quickly, you may not think much of the problem at first since your car will still keep running. However, poor acceleration is not a problem that you should ignore, as it can lead to more serious engine and performance problems with your Nissan later on. A problem with acceleration can usually be linked to an issue with the car's mechanical system, which means a trained Nissan mechanic should address the problem before it gets too bad. A mechanic can take a look at the car's engine to see where the problem lies. While the issue may stem from several causes, these are some of the most common engine ailments.