1991 GMC Sonoma vacuum

you probably have junk in the pipe ging to the throttle body. if you get some choke cleaner and spray it in there and let it soften the junk up a little then just shove it into the intake and hook up the hose. Although change your pcv valve if you haven't already and make sure y our hose going to the throttle body isn't soft. You may hear some noise with the carbon smacking around after you start the engine but it won't hurt anything. You might need a small screwdriver to drive the stuff into the manifold but take your time and twist the screwdriver like a drill, but don't use a drill....