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I have a vac line coming off the right side of my '93, LT1 that comes off the top manifold fitting, Ts and goes to the back and front of the car. The line going back To again and escapes in plastic conduit. The front line goes under the throttle body, over the water pump then is just hanging there below the engine. Any thoughts? I can't find a decent digram in the service manual or even when I Googooed (sp ; ) it. I'll try and get a semi-decent picture as they are worth 1000 slowly typed words..... Where does '2' go to?
I have a vac line coming off the right side of my '93, LT1 that comes off the top manifold fitting, Ts and goes to the back and front of the car. The line going back To again and escapes in plastic conduit. The front line goes under the throttle body, over the water pump then is just hanging there below the engine. Any thoughts? I can't find a decent digram in the service manual or even when I Googooed (sp ; ) it. I'll try and get a semi-decent picture as they are worth 1000 slowly typed words..... Where does '2' go to?
Check to see if there is a vent port coming out of your opti.....it may have been replaced with a vent type.
It is coming off the top of the opti. Just throw a Golf tee in the piece that taps of the engine.and plug the other in also. Vented means nothing unless you park in a climate controlled garage. I know i have a 93 i bought new and any change in temperture starts corrosion in the opti.
Vented is the way to go… I don’t agree that there are only certain scenarios where it is needed. The high voltage spark generates ozone which accelerates corrosion…plus if moisture ever seeps in there is nowhere for it to go. Also GM added the active venting in the later years for these reasons.
here is the petris setup that has a retrofit harness for vacuum. Note it comes off of the bottom not top!
Petris opti note two hoses…one is vacuum the other is clean/filtered supply air
Top down
Installed
I much prefer active vented…this is what happens eventually without it
It would be very hard to get to the underside of the opti without removing things… you would have to do it from below. The crank pulley, wires etc…will be in the way… you may get lucky and be able to slip on a new hose onto a fitting by feel…
If done properly your setup should have a vacuum hose and a supply air hose.
Vacuum line to nowhere
