Anybody using Autometer 9123 tach adapter?
#1
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I have speedhut gauges in my 71 Cutlass, but have never been satisfied with the tach. I was not able to get a signal from the E38 ECU despite plugging into pins that might have made that work. Eventually Speedhut had me splice into one of the coil wires. The rpm signal has always been splotchy (my technical term); does not rev smoothly, and even seems to lag. I trust it completely in steady state to know my RPM but I don't trust it at all to take it to redline. Would love to have a reliable tach to use with my T56. Anybody have any experience with this?
#2
TECH Addict
iTrader: (2)
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Before spending $189, did you try the resistor on the tach wire? I've not had any issues running older or aftermarket tachs on newer GM PCM's with the pull up resistor method.
Dig... http://lt1swap.com/lsx_tach.htm
Dig... http://lt1swap.com/lsx_tach.htm
![](http://lt1swap.com/pictures/tach_circuit_fix.jpg)