I am instaling an APEXi SAFCII on my supercharged Esteem engine that is wired with a MSD BTM with the MSD tach adapter. As per following diagram, I should take the the RPM Signal from the white wire, but the piggy back does not sense any signal from ther. With the NEG coil wire (Brown/White) and has a very irregular signal (from 800 to 3.000rpms at idle).

Neg Distributor wire neither got a signal (blue one from camshaft position signal)

My esteem engine is the old model, with one coil and distributor.

Any idea why I can not get a rpm signal?

http://www.davebaxterjr.com/btm.jpg