Jfoust

I have an 84 with a stock tach and while I have searched and searched I fund this but don't understand where he has it wired???

http://www.mindspring.com/~jayk3/toyota/tachmod.htm

and will it work for the v8 conversion or not?

Any help would be great.. thanks guys!!

peow130

Well, it says for V6, so its pretty unlikely it'll work for a V8.


The other method requires turning the screw on the back of your dash cluster..
If you read it correctly, you turn it until the rpm on the tach, matches the rpms of the engine. aka, you need a test tach or something.
Pretty simple.

Jfoust

yes it does say for the v6 that's why i ask is cause your using a poytentionmeter which you can lower the ohm's for such app. I just don't understand how he has it wired.

Jfoust

so I just couldn't wait and stumbled across another guy who did this and explained it more.. So I decided to do and it work's for anyone who want's to do this for your v8 conversion too!! just wish the stock tack was extremely responsive like to quick throttle inputs.. oh well I still have stock appearance

peow130

"Jay Kopycinski documented his 4.3 conversion and described how to convert the tach on his vehicle. He describes using a ten turn pot (5k ohm) on the tach posts. I went to perform this modification on my 1990 4Runner SR5 which now has a V8.

I found that there was already a small white potentiometer on the circuit board of the tach. I took an original reading (42.5k ohm) then reinstalled the tach into the instrument cluster. I removed the speedo to gain access to the philips style screw on the little white pot on the board (it points towards the speedo). Then I reconnected the instrument cluster (temporarily), started the vehicle, and adjusted the pot until the factory toy tach matched the actual RPMs at different key RPMS (ie. 2000, 2500, 3000, ....). Bingo! No modifications required!
Works very well. The final reading on the little white pot was around 31.1 k ohms. My guess is that you should probably be able to make this adjustment on most post-1990 vehicles (have received confirmation this works on a 1995 model). Time to do this adjustment, about 30-60 minutes. Sure beats having that other tach mounted to my steering column ! And just as accurate."