Ok all that linkage under the hood.. is there a guide on how to make sure its all adjusted correctly?

because i have this "Friend" that adjusted them all on "his car" to attempt changing the idle then "he" realized there was an idle screw seperate from all of that that did the trick.

"he" said they are ALL out of adjustment it seems.. but the car is still driveable.

Thanks
1981 300SD Turbo
"dan"

 

Service Manual CD on ebay has a discription of ajasting linkiges.