problem with defi rpm gauge

[fax0815]

Hi,
I´ve been thinking about what´s going on there...

In my opinion the NE signal is wrong! The tacho worked inaccurate (but it worked) conected to the neg. side of the coil. This gives a peak signal for every spark, the contolunit (set to 4 cylinder) calculates the rpm based on that.
Now its conected to the rpm singnal from the dizzy, providing a square signal, but way to much peaks (did not count the teeth on the triggerwheel) compared to what the signal from the coil.
To much peaks explain why the gauge goes straight to the top as soon as the engine starts.
Wrong signal...

My idea is to use the signal from the 4 tooth trigger wheel that the dizzy also provides.
Does anybody know to wich pin it is on the ecu? Is that the IGT signal you´re talking about?

Hopefully it works