Ecumaster forum

Hello everyone, new to the board here.

I have searched but I do not see but one unanswered thread.

I have done a swap in my Supra and I get a tach signal that reads out but is intermittent and cuts out. The input to the cluster should be a 5v square wave signal.

I have a feeling I will need to get an adapter for the signal, can anyone chime in on this?

Thanks!

The EMU outputs a 5V square wave signal. An intermittent issue indicates a bad connection, a pin that wasn't inserted properly, etc. The Mk3 Supra doesn't need any kind of adapter, the output from the EMU will drive it properly.

Thank you for the reply, I will see what is up but I have not pulled the cluster and tweak did the rest.

Ah the little issues we face lol.

I think you can only use Aux OP#4 as it has the pullup voltage to make 5v sq wave

Okay, I have an update on this. When the laptop is connected to the ECU it seems to cut out, but when I have the computer disconnected it never seems to cut out.

Maybe a firmware issue?

Hi,

In my Nissan Skyline I quite frequently get my rev counter suddenly dropping to zero and then back to normal, it happens seemingly at random so isn't too much of an issue.
I noticed that the EMU manual states that AUX4 is for tacho, however I downloaded the setup and wiring diagrams for fitting the EMU to an RB25DET Skyline (mine are RB20 and RB26 but the wiring is mostly the same) and the pinout provided and the basic map file is set for the tacho to be on 'pin G3 Stepper 2 winding A'
I was going to switch the pins and move the Tacho to AUX4 and test it but as my ECU is behind the trim panel I have been waiting for another reason to go in there.
I am wondering if this could be the reason my rev counter drops out and if so why the pin out for the RB is set for a different output.

Edward.

RHD wrote:I think you can only use Aux OP#4 as it has the pullup voltage to make 5v sq wave

Seems rather like ground loop when you connect laptop.

rpk2012 wrote:Okay, I have an update on this. When the laptop is connected to the ECU it seems to cut out, but when I have the computer disconnected it never seems to cut out.

Maybe a firmware issue?

Swapping to AUX should help in your case.

Mobilelpg wrote:Hi,

In my Nissan Skyline I quite frequently get my rev counter suddenly dropping to zero and then back to normal, it happens seemingly at random so isn't too much of an issue.
I noticed that the EMU manual states that AUX4 is for tacho, however I downloaded the setup and wiring diagrams for fitting the EMU to an RB25DET Skyline (mine are RB20 and RB26 but the wiring is mostly the same) and the pinout provided and the basic map file is set for the tacho to be on 'pin G3 Stepper 2 winding A'
I was going to switch the pins and move the Tacho to AUX4 and test it but as my ECU is behind the trim panel I have been waiting for another reason to go in there.
I am wondering if this could be the reason my rev counter drops out and if so why the pin out for the RB is set for a different output.

Edward.

RHD wrote:I think you can only use Aux OP#4 as it has the pullup voltage to make 5v sq wave

Just a random thought:
In your rev limiter table, did you check "cut spark during overrun"?
I did this and it causes my tach to drop to zero every time Idle circuit switches on (like when I shift gears). This is in a mk3 supra with aristo harness and my own jumper harness