Lifetime Supporting Member
Join Date: May 2002
Location: Gypsum, Co
Posts: 8,468
Start by finding your vacuum manifold and getting some caps to go on the lines.
Then pull one off at a time and plug it, then see if there is a difference in the air flow. This will eliminate all the lines but the ones for the HVAC system but it will give you a place to start.
96 F250 PS XLT 4X4 long box, 5sp,4.10, manual hubs,pyro+boost guages, Dark Toumaline, add a leaf, Dale's TYMAR, and HX hose, downpipe, coolant filter, Luk clutch