Adjusting injection pump on 85 300SD????

Old 300SD is running a little rough. Does anybody know does
that little bolt adjustment screw in toward the pump????
Or does it screw out, towards the dash. I tried screwing it out and it seemed to smoth the idle. Car only has 182,000miles on it and now seems to smoke a little. Should the adjustment help???? Or is there something else???? Thanks in advance....