87' s-10 Blazer, 2.6L V6. Getting vacuum from ports serving PVC valve, EGR valve and MAP, but not the port that supply vacuum to ACC items such as HVAC controls, transfer case, etc. I have check the port and vacuum is temporary present revving the engine

 

Well figured it out, who ever last worked on the throttle body switched the ports between J (EGR) and S (HVAC controls, transfer case, etc).