Hey does any one know where do I begin with problem Loss Of Power & Acceleration on my 1990 300zx non turbo Automatic. It all started when I put arebuilt trans in and bought a new throttle positioner too because after I put in the trans the car was still wining out through the gears the throttle positioner fix that but I was wondering if not calibrating it is what's causing all this sluggishness. I went on a road today and it could not get enough speed to the freeway. then trying to pass a car to took for ever to get up to speed and any one that owns for 300zx to go slow is very strange because they really race up to speed. so please let know what to do. thanks