Well I have a 1986 300zx turbo 2 seater in excellent condition..(ANd I do mean excellent). The problem that I have with the car is that between 1st 2nd and 3rd gear the car has verly little power. ONce you get in 4th and 5th gear you are cruzing...It is very sluggish between these gears after long trips of driving. I was suggesting replacing my air flow meter and adding a K&N filter in and putting in a new exhaust and muffler. I have replaced the TPS (throttle position sensor) Heat temperature sensor, cap and rotor spark plugs and the Nissan dealer did a fuel injector recall. I also changed out the plugs and had the oil changed..This contributed alot to the performance of the car but like I said the problem still exists. I only have 112K on the car and the engine is in good shape. The other problem I have is I noticed when the engine is not warm and the engine is cold, I have to turn the car over twice in order for it to start...It will turn over fine as long as the engine is somewhat warm.....Can anybody help me out on this?