where to get tacho signal? GQ dizzy to V8

[grazza]

Anyone know where I can get a tacho signal on my Toyota V8, twin dizzy, twin coil.
I am interested to see if I can get any response on my GQ (six cyl) tacho.

Noticed that the back of the tacho has an adjustment pot - maybe I can play with it using a V8 (4-cyl) signal

[slowhilux]

Spot on. The 1UZ puts out a 4cyl signal. Alot of Toyotas have a tacho adjustment in the back of the tacho too! I will chase up some wiring diagrams tonight and find the ECU pinout for the tacho signal.

Phill

PS:- glad i could help with the other problem too

[slowhilux]

OK, got the diagrams. As you already know, there are 2 x coils, 2 x igniters and 2 x dizzys. On Igniter #1 there are 5 wires, and #2 only has 4. The tacho signal comes directly from the 5th wire on igniter #1 (which is in the 4th pin on the plug), its a plain Black wire, no other markings (no dots or stripes). If you look at the 2 igniters, you will see what i mean. It will give out a 4cyl signal.

If you cant adjust the GQ tacho to suit the 1UZ, any good instrument shop will make it work with a 4cyl input. Shouldnt cost more than $50.

Hope this helps,
Phill

[grazza]

Thanks for your help Phil.
I will have a crack at it this afternoon...