I am back to fixen my 82 Diesel and I am wondering what my 3b should act like. It idles at about 500 and its rough and noisy. It has loud clackin top end. It seems to run and sound better when I give it throttle. I am still running fuel that sat last winter or longer. I just got the truck in april and had to fix electrical issues so it would run, I changed the fuel filter and added some diesel treat but never changed glow plugs. Do I need to get the injectors cleaned and timed and what else should I do? Any help would be appreciated.