When i am at a stop my tach will quickly drop to 0 and then jump back up to idle again, but the engine isn't stumbling and I am not having a noticable idle problem. I don't have this problem when driving. I am not getting any codes thrown either. Is there something wrong with my distributor or is the problem coming from somewhere else?

 

could be the alternator is on its way out, i noticed this happened to me just before my alternator took a ****.
i think it has something to do with the voltage regulator. try starting the car and put a multi meter on the battery and see if the voltage jumps. if it does thats your prob.

 

would the voltage jump just on start up or while running? You don't even use your alternator on start up right?

 

kind of hard to tell from what you've described but I had a similar problem when the tach would bounce up and down during idle and low rpms and turned out that my ICM was going out.

It lasted about a month doing that until it just went completely out and I had to buy a new one.