Speedo way off after swap
03-29-2015, 07:30 AM
#1
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Speedo way off after swap I've got a '94 Z28 that I recently converted to a LS1. It's a 6 speed (always was), and everything works great except speedometer. It reads way low now. Was working before swap. Now it's really slow. Says I'm doing 10-15 mph when I've got to be going 40-50. Has anyone else had issues like this? Is there an easy fix?
Thanks for the help.
Thanks for the help.
03-29-2015, 07:48 AM
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The automatic and manual use different triggers for the speed sensor on the trans. It can be changed in the tune, but if you said it was always a manual it shouldn't be the problem.
03-29-2015, 09:22 AM
#4
I've got a '94 Z28 that I recently converted to a LS1. It's a 6 speed (always was), and everything works great except speedometer. It reads way low now. Was working before swap. Now it's really slow. Says I'm doing 10-15 mph when I've got to be going 40-50. Has anyone else had issues like this? Is there an easy fix?
Thanks for the help.
Thanks for the help.
93 is a unique year. Your 4L60 may have been a 40 tooth reluctor. A 1993 T56 is 17 tooth or 11 tooth reluctor. Did you change the PROM in the ECM?
03-29-2015, 11:12 AM
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I have a T56 from a 98 Fbody. I know my Z28 came with the performance axle which consisted of 3.23's. It has a 150mph speedo. I ordered a computer from someone and told him what I had and he adjusted the parameters. The rpm is correct, but the speedo only reads half of what I am actually doing when comparing to GPS.