i just bought a 1991 z28 and the tach and speedometer do not work. the speedometer does not move at all and the tech is off. it idles aroud 4500 rpm and goes way past where it should. the guy i bought it from said it needs a speed sensor... any suggestions?

 

Common 90-92 problem

https://www.thirdgen.org/forums/elec...meter-fix.html

Maybe .
Speedo signal goes from VSS in trans to computer to speedo itself so fault could be anywhere;
Possibly as simple as the plug being off the VSS or complicated as the gears that drive the VSS being stripped

 

thanks ill have to look at it closer this week and let you know what i find

 

whats involved in changing that, and where can i find one, i have the same problem, I am aware of the tach issue and the fix but not on the gear that drives the VSS

 

ssame issue with my 91 z28 i pulled and replaced the vss and still no read on the dash...and i cannot find anywhere that sells the gears for the speed sensor (although mine looked fine when i pulled oout the old sensor... im lost and im alsomst ready to throw a tarp ove rthe car ive had sooo manyy electrical issues with her S.O.S PLEASE HELP ME

 

I know the tac problem on my 91 Z, but my speedo is an intermittant thing. If it rains out, or sometimes if I take a left turn, it will jump a round a lot till I drive it about 10 milesor more then it works fine for a while. Checked all the wires I could find from dash to vss and still cant find problem. Thinking of parting this out if I cant resolve it.

 

I hear ya, the electrical problems in this car is so bad, (and it is stock), that I ffeel that I should just part the SOB out if I can't drive it.

 

I don't have the details on this year tach. But the problem might be related to a similar (I think) tach from the 80s. I described the issue & the fix for mine on PHOTOBUCKET, sub album SPEEDOMETERS & GAUGES, pictures 5-8. My problem was noise coming into the power supply. good luck, Bruce Roe

http://s93.photobucket.com/albums/l7...0and%20GAUGES/