When I took off the plenum to replace the fuel pressure regulator in my 1998 blazer, I found that the regulator installed did not have a vacuum line attached to it. Where is the vacuum source located? I have looked everywhere and I must be 'blind' (or stupid). There was no vacuum hose there that came undone. Help is needed badly. Thanks!

 

The FPR is in the vacuum source. Nothing connects to it because it is located inside the intake manifold. Nothing to worry about!