|Originally posted by Jayfelt:|
So randomly out of nowhere my Fiero's miles jumped from 110,000 to 210,000. Not sure if it broke or if it was rigged way before I got the car. Any ideas?
The Fiero's odometer is gear-driven by a pair of motors (one for the speedo and one for the odometer) that work off of the VSS.
(M is for miles, K is for kilometers)
I don't have a picture of the back-end of the odometer, but basically, there are a series of plastic gears pressed onto two (three?) metal rods. As these motors turn those rods, the gears move in conjunction to properly turn the speed. What happens is that the plastic gears will dry out and split... somewhat like a "pacman" type of shape, though not so pronounced. This allows those gears to occasionally slide up and down the rods where they otherwise should have stayed where they were. This can cause what you're seeing.
The Fiero's speedometer is fully rebuildable, so you can basically take it apart, and fix the 2 and turn it back to 1... and even replace that gear.