Intermittent speedo/running problem 1992 XJ

[will_yetter]

Hey everyone, first post so sorry if I do it wrong. My rig is a 1992 Jeep Cherokee with the 4.0 High Output motor, AX15 5 speed, NP231.
My speedometer occasionally stops working, and for some reason ONLY when that happens, my Jeep runs all loaded up, doesn’t want to idle, and backfires a ton. Are there any possible ideas as to what this might be??? I’m completely stumped on this.
Thanks so much,
Will

 

[Anak]

It sounds like you have a problem with the vehicle speed sensor.

It looks like the '92 is a very different animal from my '96, so I am not sure what to advise in pursuit of this, but if the sensor is giving the computer bad information it is likely to be the cause of some problems.