i have a 91 z and the speedo goes crazy when its plugged in. i'll only be going like 5mph and the gauge will peg out then go back to zero. also the tranny tries to shift into overdrive . i unplugged it and the tranny shifts ok at best. i have no idea whats goin on with it, anyone know a solutiuon?

thanks

 

well i havnt worked on a 91 and i know they have a different electronic speedometer so i may be totally wrong here but in previous years the trans would send the speed signal to a "vehical speed sensor buffer". What it does is conditions the signal into a form the speedometer and the ECM can use and the ECM uses that signal to determin things like the torque converter lock up. So you may want to look there and see what if its ok.

 

rolling thunder, thanks for the quick reply. i have actually found out why the speedo isnt working.......apparently, who ever had the car before me had put a 4L60 vss in instead. WTF! i'm getting the right vss and, hopefully, that fixes it.

 

Yea it was funnie i was think thats odd the 700r4s shift points arnt controld by the computer? Well that explains it lol

 

Wait a min the 700r4 is the 4l60. I was thinking u meant 4l60E because that trans does have electronically controlled shifts.