Hooked up the laptop to the IROC the other night when I had to go into work (pretty uneventful datalogging). However, on the way back the "dash" portion of winaldl showed my mph steadily increasing. At a stop light the mph would drop to zero. When I was traveling 45 mph by the speedometer the "dash" on the laptop screen indicated 60 to 65 mph. Once I got on the interstate and was running 65 mph (by the speedometer) the mph incated on the "dash" screen of winaldl gradually climbed to 100 mph. When I enabled the portion of the program that showed trouble codes it checked vehicle speed sensor (VSS) even thought the check engine light was not lit.

By the way, 86 IROC, 305 tpi, 342 pos rear end, 700r4 transmission. The speedometer has a cable off the transmission not the electronic speed module as on later cars. Anyone else havea similar problem.

 

No one else has seen a (large) difference between the speedometer and the speed indicated on the "dash" for winaldl? It doesn't seem to affect the way the car runs or the mileage, I'm just curious.