Yes I v already searched about it
and found out that I can tap a signal from the ECU box
i do have a diagram and the number of the socket of the tack signal
(N3/4 pin18 at the box or 0.75 green/yellow from X81/4 which lead to the A1 instrument cluster)

I just want to ask for an alternative or a more simple way
Is there any place where I can tap the signal from ?
Is there any place would provide a signal that may equal to the Tach signal?

ps.My additional injector control box require a tach signal to operate.

Thank you very much