Unknown line.. vacuum maybe??

2000 gt I'm working on a brake problem so I'm bench bleeding MC but as I'm taking it off I see this strange line. Its unplugged, incredibly small with a 90 head on it. It's coming out of the harness opening that contains the lines for spark plugs and injectors on the drivers side. What the hell is it lol???
20191119_125935.webp
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20191119_164333.webp
 
2000 gt I'm working on a brake problem so I'm bench bleeding MC but as I'm taking it off I see this strange line. Its unplugged, incredibly small with a 90 head on it. It's coming out of the harness opening that contains the lines for spark plugs and injectors on the drivers side. What the hell is it lol???
20191119_125935.jpg

It's a ground wire...it attaches to the stud on the fuel log directly above your index finger in the photo. Verified visually on my 2K GT. Cheers!