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Tacho output

Posted: Wed Mar 02, 2016 2:19 pm
by VFRegal
Hi everyone.
I have an issue with not 100% Nistune related.
I've fitted an Apexi AVC-R to allow me to control boost via rpm.
I am having some issues with the tacho connection.
When I connect the tacho wire to the ecu I lose my tacho on the dash and the it seems also the tps signal. The car runs terribly.
If I remove the tacho wire it goes back to working ok.

I currently have the AVC-R wired as per the instructions with power and ground taken from the ECU.
I have tried to Tee in a 10K Ohm 0.5W resistor to a 12V supply to pull up the voltage but this had no effect.
Is there a trick to get this working or can I take the rpm signal from somewhere else ?
The car is a S15 if that helps.

Thanks,

Peter

Re: Tacho output

Posted: Thu Mar 03, 2016 7:01 am
by Matt
This should be in the 'general mechanical' section . Not sure but try a larger value resistor perhaps, you are shorting out the tacho resistor (preventing it working on the dash) and may damage the driver in the ECU

Re: Tacho output

Posted: Thu Mar 03, 2016 3:54 pm
by VFRegal
Hi Matt,
Sorry to post in the wrong area. Feel free to move it if required.
I am a little confused. You say not to do it as it could damage the ECU but to try a different resistor ?

Is there somewhere else i should take the rpm signal ?

Re: Tacho output

Posted: Mon Mar 07, 2016 7:47 pm
by Matt
Only from the ECU tacho output. If it stops the tacho working, then the feed you are using its shorting the output. Increasing resistor value will low the current used. Double check with your tacho install manual