[Gmecm] a question of timing

[Don Brown]

My question below is about the reference signal.  The application is

buick 455
90 corvette TPI (vin 8)
electromotive hpv1 dis


The tpi to buick is bridged by an adapter that connects the two.

My corvette manual comments that the reference signal provides both rpm and crankshaft position.  It doesn't say what the amplitude of the reference signal is.

Since the hpv1 has it's own advance curve I'm going to use it for the timing.  But can I use the tach output from the hpv1 for the reference signal into the ecm?

My original plan was to just plug the distributor hole with a fixture that would still turn the oil pump.  But as I was thinking (a painful process for me), the tach output is not going to be 8 pulses for each revolution of the distributor that the distributor would provide.  I have since modified a distributor to provide the reference output needed by the ecm.  

I think that I've answered my own question here but some comments would be great since I don't think of everything.  I believe that I'll need the reference signal from the modified distributor to give both tach and crank position to the ecm (16197128) since the tach signal from the dis won't be giving crank position.  I'll still be able to use temperature and map to adjust fuel delivery and will program the ecm to work with the dis

A little additional thougt tells me that If I use the curves in the dis, I don't need a knock sensor.  And hopefully I can adjust the hpv1 to eliminate the need for it.

Does anyone know what is the amplitude of the reference signal is?

Thanks in advance for all comments.