RB25 S2 into 89 TACH PROB

[jacksonbrown]

Well I've spent countless hours on this site and others trying to figure this out and one thing I have noticed is how many other people have the same prob. I think there's a lot of people using the same couple swap writeups and not catching the error. My tach did work with KA, swapped in RB and nothing. I do have a small varying voltage at tach output but factory or aftermarket tach does'nt work. I do believe I have a ground issue in the dash just wondering if anybody has had same prob and figured this out . Would just like to add that the info I have got from this site has really helped and engine is running great, just trying to get everything working since I'm building this for my son as his first car. Thanks for any help. Adding some pics of how its going

Modified by jacksonbrown at 6:41 PM 1/22/2008

Modified by jacksonbrown at 6:45 PM 1/22/2008

Modified by jacksonbrown at 6:45 PM 1/22/2008

Modified by jacksonbrown at 6:57 PM 1/22/2008
Modified by jacksonbrown at 7:22 PM 1/22/2008

[jacksonbrown]

Anybody got a RB/240 in the central FL area?

[lilskyline240]

u cant use a 89 or 90 tach cuz they are for a SOHC motor and no matter what the signal from the ecu wont work. U need a DOHC tach and it needs to be calibrated to work correctly with the 6 cylinder engine