Autometer Tach Reading Incorrect
07-13-2009, 11:37 AM
#1
Staging Lane
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Autometer Tach Reading Incorrect I have an Autometer TACH ultra light II and i can't get the thing to read the correct RPM's any ideas? sent it to them for repair and they said it tested good ....i install a freinds Phathon gauge and it seems to work but the needle fluttered at idle (800) once you start to rev it smoths out the needle.
ANY IDEAS??
The tach is set to 4 cyl ( I also tried the 6 and 8) my computer is from Speartech and apears to be a Trailblazer SS 2007
HELP!!!!
ANY IDEAS??
The tach is set to 4 cyl ( I also tried the 6 and 8) my computer is from Speartech and apears to be a Trailblazer SS 2007
HELP!!!!
07-14-2009, 04:04 PM
#3
TECH Apprentice
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I had a similar problem with my LS2 and an '04 GTO ECM, might be a similar issue to yours. I don't have all the details, as the real troubleshooting took place by the guys who built my harness: Fuel Injection Specialties - http://www.fuelinjection.com/
I used coils that were not normally used with '04 ECM's, so the ECM didn't recognize the wavelength being sent by the coils. FIS added an inline "signal calibrator" to modify the tach signal into a wavelength readable by the '04 GTO computer. With this one modification, everything worked. I don't have the part number for the calibrator, but they can probably point you in the right direction.
I used coils that were not normally used with '04 ECM's, so the ECM didn't recognize the wavelength being sent by the coils. FIS added an inline "signal calibrator" to modify the tach signal into a wavelength readable by the '04 GTO computer. With this one modification, everything worked. I don't have the part number for the calibrator, but they can probably point you in the right direction.
