There are 3 pipes that go into your throttle body and you should use some JB Weld to permanently epoxy them into place. If you’re standing by the LF tire, there’s 2 AL pipes that go into the throttle body from the R and one on the L. The ones on the R go to the over complicated brake vac system. The one on the L goes to the Idle Air Control Valve (IACV). They’re supposed to be a press fit but in our old cars they get sloppy loose and become vac leaks.
How to fix. Pull the AL pipes out of their ports, clean the mating surfaces with brake cleaner and a little scrubbing, then fasten them back up with JBWeld or some kind of epoxy.
I fooled with 4 other people’s cars this weekend as I modded them to take the MAF so we could do more testing. Everyone of those cars had 3x loose pipes going into the throttle body. One of them, we expoxied up at the track.
How to simplify the over-complicated brake booster vac lines. Simplifying vacuum lines