S13 RB25DET SII Tach wire problem

[bkos90]

I just swapped a RB25DET into my s13 and the car runs great and all but my tach isnt working. While i was doing the wiring harness i noticed that there was no tach sinal wire coming from any sensor on my harness because the harness was a little messed up. All i want to know is where is the tach sensor so i can get a wire connected to it to have my tach working. Thanks

[platez808]

no such thing as a tach sensor. ecu makes the tach signal based off info from the cas.. even if you have a tach signal though, it wont work on your stock tach. you either replace it or modify it to work

[bkos90]

no such thing as a tach sensor. ecu makes the tach signal based off info from the cas.. even if you have a tach signal though, it wont work on your stock tach. you either replace it or modify it to work

Its not reading at all... and i have seen people with the dohc clusters, they work but need to be calibrated because they read 1.5x more than the stock because of the 2 extra cylinders.

I looked at the wiring diagram and its showing that the tachometer wire goes from the ecu to the "Test point tachometer out"

[platez808]

Its not reading at all... and i have seen people with the dohc clusters, they work but need to be calibrated because they read 1.5x more than the stock because of the 2 extra cylinders.

I looked at the wiring diagram and its showing that the tachometer wire goes from the ecu to the "Test point tachometer out"

Well thats what i meant by modifying it.. But personally i opted to use a tach from a 95-99 maxima. It can also be found in I30s. They look exactly the same as the s13 tachs minus the clock so it practically looks stock and you dont have to really mess with the tach since it is already calibrated to work with 6 cylinders (only have to do a few mods to make it work and fit in the s13 cluster) Theres a write up on here on how to do it.

in terms of the wiring, you should check for connectivity from the tach to the tach signal pin at the ecu and thats it. dont worry about any thing else. when you are absolutely sure you have connectivity and it still doesnt work, then chances are you have a bunk ecu. open up the ecu and check for any signs of burns and what not. i have a thread all about my ecu with the fried tach signal resistor. i bought another ecu and that solved my prob.

good luck

[bkos90]

Well thats what i meant by modifying it.. But personally i opted to use a tach from a 95-99 maxima. It can also be found in I30s. They look exactly the same as the s13 tachs minus the clock so it practically looks stock and you dont have to really mess with the tach since it is already calibrated to work with 6 cylinders (only have to do a few mods to make it work and fit in the s13 cluster) Theres a write up on here on how to do it.

in terms of the wiring, you should check for connectivity from the tach to the tach signal pin at the ecu and thats it. dont worry about any thing else. when you are absolutely sure you have connectivity and it still doesnt work, then chances are you have a bunk ecu. open up the ecu and check for any signs of burns and what not. i have a thread all about my ecu with the fried tach signal resistor. i bought another ecu and that solved my prob.

good luck

Will my rev limitter still work if i have a bad ecu? im gonna check for continuity today but i just wanted to make sure that i still have rev limmiter. thanks