For some reason I can't get this car to go over 100 MPH. I've only recently purchased it, and the prior owner had the top end replaced, and otherwise the car accelerates fine, etc. But at 100 MPH my foot is all the way to the floor and the tachometer is not even halfway to redline (like just below 3,000 RPMs), but the car just won't give any more. Do I have to adjust the accelerator cable? Could it make any difference that the car was purchased from a guy a 1000 feet above sea level and now it's less than a hundred feet above sea level?