Slow Tach
 

Hello guys need some expert advice here....

69 camaro - ls3 - stewart warner max gauges (Simular to charley's jackass car)

RPM appears to be very accurate but very slow to react.

Wired using the white wire from the ecm 2pulse.


I read where I might need a conversion box autometer 9117 or a resistor....

A tachometer signal is included in the bulkhead connector (see
below). This is a 2 pulse/rev output which may correspond to
a 4-cylinder setup in some tachometers or transmission controllers.
Note the signal is a low voltage square wave, some tachometers or
transmission controllers may need a pull-up resistor in order to read
the signal, similar to a 5000 ohm, ¼ watt resistor– this detail is left to
the user. The following circuit has worked for numerous devices – the
resister value may need to be changed if your device does not read
this output properly.


Any help would be greatly appreciated!!

Try a half watt resistor.

I recently helped a friend with an issue with his 67 Camaro. He was running an 06 LS2 GTO setup (E38 ECM, IIRC)

At any rate, the ECM would only allow for pulse output. Through some testing I determined that the Camaro tach expected a 6 cylinder input. We had a Dakota Digital box in place to do the translation. The RPM was fairly accurate once we figured all of this out.

Unfortunately, his tach is slow as well. My sample size is 2, but I'm inclined to believe this is the way they are. If you learn more, I'll be very interested!