My carb is either running to rich or too lean. It backfires when cold (untill it warms up) and pings on the highway at about 2400-2700rpm. I just moved from high altitude to low and I am thinking the carb now needs adjusted. I need advice to rich or too lean? And when I adjust it how do I adjust it just right? I have a 1987 FJ60 and the carb is only two years old.