I have been hearing a strange noise that is progressively getting louder, almost sounds like a small motor running, or better yet a slight grinding sound, I've traced the sound to this area:


Upon further snooping around I found that if I pinch off the #20 hose shown below the sound will stop, let it go, it starts back up agian. I was wondering if there is anything that could be going or is it perhaps a blocked line or I don't even know where to start looking for what the sound is, I just replaced the fuel filter and thought maybe if something was loose it would be knocked back into place but to no avail. Any help would be GREATLY apprecaite. At 286,000 miles why would anything be breaking?? lol. Here's the hose I pinched to stop the sound.

 

Nobody has any idea what that #20 vacuum line controls?

 

open that black box and check it out...i know there is a mapsensor in there for sure..but other things i dont pay attention to..

 

No idea what vacuum #20 is, but that's the PGM-FI box you've circled, and it has all sorts of vacuum activated controls in there, including a few solenoids I think.

Take the PGM-FI box, open it up, and trace where #20 goes. Likely whatever solenoid it's attached to is going bad.

 

Wasn't too sure what was in the box so I was a bit apprehensive about taking it apart. Is it just the two screws on the top and it snaps open? I took those off and started to pull and thought better of it.