Help identifying vaccum line

curiousone940 · curiousone940's Garage

Subject P-car, a 3.2 '89. I recently noticed what appears to be a vacuum line (about 4-5 inches long) on the back side of the throttle body, which was connected on one end (I am guessing perhaps the throttle valve) but the other end was loose. The only other connection point I could find for this line was right back to another nipple on the throttle valve (?) itself, which essentially would just make this line a loop back to where it starts. I've looked at Bentley and even the factory service manuals and I'm still not real clear on where this line should traverse. With the engine running, I cannot detect any actual vacuum on the end of this line and the engine itself seems to run just fine. Wazzup here??? Thanks for your help!!

ChrisBennet · ChrisBennet's Garage

curiousone940 · curiousone940's Garage

Appreciate the pic; it would be helpful if I could get as good of a view of mine as yours, but as best as I can tell, we may have a different set-up. Mine has the two nipples on the throttle valve like yours, but I think I only have two other vacuum fittings on the throttle body itself (yours apapears to have perhaps three fittings on the throttle body). One of my throttle body fittings has the Y-connection just as yours (one of those lines to the pressure regulator and the other to the damper)...the other fitting (the one in your photo that looks to be brass with nothing attached) has a vacuum line attached whose function is unclear to me (the line attached to my fitting is not smooth rubber, but one having a braided cloth exterior feel to it, and when disconnected, it definitely makes the engine run rough). IF this photo is of an '86, is it possible these vacuum fittings changed somewhat to the '89 model???

curiousone940 · curiousone940's Garage

Chris....Mea Culpa Stupid!!

While re-examining my vacuum lines/fittings, I just happened to notice a decal/placard on the inside of the hood with a relatively clear vacuum hose routing diagram. I have now found where all vacuum hoses belong and appreciate your help in concluding this little project. Thanks again!!