I was replacing the spark plug wires on my 1996 Chevy S10 Blazer 2WD today. I think I knocked a hose off somewhere. Underneath the Vortec is a silver valve that is sucking in air. I place my finger over it and feel suction. The engine runs weird and sputters when the valve is open and no pressure. I have a few hoses in the right section of the engine compartment but not sure how they go together. #1 is a wiper fluid hose from the reservoir. #2 is a wiper hose going to the hood wipers. ( I assume #1 hose just connects straight into #2 hose). Then There is a larger hose that connects into a T-valve style connections, then connects to a sphere vacuum on the underside of the hood. Please if you know how these work, reply. Images provided, and yes I spelled Vacuum wrong in the pictures.

 

That looks like the main vacuum source on the engine. That should connect to the open spot on the check valve / 'T'.