If you do get a pressure tester, in addition to smelling for gasoline in the vacuum line you can check the pressure regulator by pressure. Get a steady reading, then remove the vac line ... pressure should increase around 10 psi at idle. If no increase the FPR is shot.

Yes, a failed FPR would give higher pressures, plus leak fuel into the intake manifold through the vac line. It is certainly worth checking it out.

Fixed.



Now that this is done, I have to attend to a large vacuum leak at an injector. Am I wrong for wanting to not yank off the upper intake and instead squeeze some rtv in there and hope it sets right?

That'* great. I'm glad we sent you down the right path.

Dude, it'* fuel! Fix it right. My opinion anyway.

you can get new orings at the parts store for a couple bucks

It'* not the cost of the O-rings he is worried about. I think on the Montana you have to remove the upper intake manifold to get at the injectors, and its a big job.

RTV would be a temporary fix at best. May save you for the time being with winter and all. But gas will invade and destroy silicone rubber. It'* not a matter of if, but when.