1967 Camaro + 2006 GTO LS2 + Autometer Tach: How do I hook up my Tach????

[1967ls2]

I have had the LS2 in my 67 RS/SS Camaro for a few years now. I have every single gauge hooked up and working perfectly in my vehicle except for my Tach. I have looked at different wiring diagrams on the internet, tried hooking it up to different signal wires from the ECM, tried switching the Autometer (Carbon Fiber Series) gauge from 8 cylinder to 6 cylinder to 4 cylinder and I can't even get the gauge to move.

First question, can anyone provide me with a definitive answer as to which wire I should be using for the tach signal out of the ECM?

Second question, should the actual tach gauge be set for 8, 6 or 4 cylinders? (Everything I have read has said 4 cylinders since the LS engine is a 2 pulse system, I believe)

Third Question, what would be the best method to get this up and running, a pull up resistor (1K ohm in line, I believe), a tach adapter (Autometer or dakota digital) or another method possibly?

Thank you all for your help, insight and opinions!

[Z06vet]

I am running my autometer right off the ecm tach wire. Speartech modified my harness, tach wire was labeed. Also need a power & ground for it. Should be set to 4 cyl. What ecm/harness do you have? How is the tach wired right now?

[1967ls2]

I am running the OEM GTO LS2 wire harness. The tach is in the dash now with all the other gauges and the only thing hooked up to it now is the light. I have tried different wires but nothing has been able to get the tach to even move. Thank you for the reply.

[neki67]

You might need to do the same as on the GMPP wiring harness with the E38 ECM. Have a look here: https://www.pro-touring.com/showthre...o-factory-tach or snoop around @ LS1tech.com.

[SSable]

Give the guys at Current Performance Wiring a call. they rewired my LS2 for my 67.

http://www.currentperformance.com/

[1967ls2]

I purchased a few different resistors and I am going to try to wire it in to the tach signal which I believe should be a brown wire coming off the C1 (J1) connector to the ECM pin 48. It seems as though I need a pull up resistor to boost the tach signal so the Autometer gauge can read it. From what I understand I need to wire one side of the resistor into the tach signal wire before it goes to the Autometer gauge and the other side of the resistor needs to go to a 12v source. I am going to try to get it wired up tonight and I will report back with my findings. I was told to go with a 4700 ohm resistor. I have a 5100 ohm resistor which should be fine. Thank you guys all for all your replies and suggestions.

[1967ls2]

Problem solved! The pull up resistor worked. 5k resistor & my tach is working perfectly. Thank you all for your help & support.