I am looking for info to adjust the fuel on my 1979 280z as it is a daily driver and it will not smog. There is no smoke, runs pretty good, but the fuel is to rich to smog. When at high ellevations it has less power than it should and when it comes down to an idle, it will run at 2500 untill I go 5 mph then calm down to 700. Is there a place to make adjustments. Air filter, oil is clean and has new plugs.