The 84-89 300zx had a fuel injector recall issued back in the 90's. It was issued becuase the injectors could leak causing an engine fire. Call your local nissan dealer about it. They'll ask you for your VIN number to see if it's been done or not. If not take it in as it is free and better than having a fire. Beware, some dealers have been known not to comply with the recall meaning they want to charge you for it but it's FREE. Also don't be surprised if some dealers don't know about it or very little about it becuase the 300zx is so old. Last time I went to my dealership one of the parts guys didn't even know what a 300zx was.