Help with tach?

[mwebber]

You guys have it easy.... try doing this in a MKII where there were no turbo clusters and the needle sweep is different.....

For the MKIII:
Change R3, R4, and R8 (maybe R1) to the 1JZ values listed in the link below.
http://www.autosoftsys.com/supra/tachcompare/

A 7M-GTE tacho should work, but I'm pretty sure it will be off a little more than a JZA70 tacho, but not by much.


lata....

 

[conundrum07]

So what was the solution? I have the exact same problem, 89 NA 5 speed chassis and the tach wont work. The wiring is correct, i have a signal all the way to the cluster plug and neither the 1J or my converted NA tach will work.

 

[inline6]

So what was the solution? I have the exact same problem, 89 NA 5 speed chassis and the tach wont work. The wiring is correct, i have a signal all the way to the cluster plug and neither the 1J or my converted NA tach will work.

The answer to my problem was that the 1j tach I got with the clip was faulty. I switched to a 7m turbo tach and it is spot on now. If you are not getting any readings at all you need to check your wiring. Maybe rewire it in. Also you can check the resistance on the back of the circuit board for the cluster and for the tach, I believe it should be 42 ohms, someone correct me if im wrong.