Black wire at cold start injector plug ?

[bta 120]

Found a broken wire (black) where the third injector plug is. seems the blue and gray wires there are ok. So the harness going to that plug has a third wire any thoughts on what this wire is or where it ties in.

 

[bta 120]

After searching may have found it. A shielding wire to ground. Also some have found the same wire snipped. Still wondering if it should be connected?

 

[Rig rocket]

I'm new to these cars but spent 14 yrs fixing military aircraft. When you find a wire like that they normally are for stray voltage discharge to a case ground or for voltage induction to discharge to case ground. F16's use them everywhere....nice find hope that helps