I just bought a 84 300ZX, it has been sitting in a garage for like 5 years so I changed out plugs,wires, gas, and battery. I was finally able to get it running and its running rough. It idles rough and when you give it gas and it hits 2000 rpm's, the rpm's drop and it almost stalls. There is also some smoke coming out the rear, but I think that is just moisture in the engine. I was also informed by the gentleman I bought it from that there might be a problem with the turbo, but I was informed that the turbo doesn't kick in till around 3500 rpm's. Any help would be greatly appreciated.