Did the jeep have an alarm/remote start? It could also be a rpm sense wire for that.

 

My son surprised me last year by having a remote start put into the XJ. Either way I'll check the integrity of the wire and repair/replace it.

 

Well, I finally got around to replacing all of the injectors. All of the connectors looked good and the wiring looked intact and insulated well.

When I started it, it started right up and idled the smoothest I've ever seen it. Throttle response was much improved too. It runs like a new engine (after 200k miles).

One of the connectors broke all of the clips so I had to zip tie it in place. I'll need to replace that one but most of the locks broke off of all of the other ones so I'll replace all of them. Will stop off at the local NAPA and see if they have them there.

I wrapped the rail and will wrap the injectors after I replace the connectors