I have a couple specific technical questions about the 7 & 8 pin ignition modules used on TPI and TBI cars.
Here is shematic photo of the module, that I found, indicating the waveforms at the module: http://www.slantsix.org/articles/dib...odule-schm.jpg
Let's start with what I think I know about the operation of these modules:
1) The reluctor style pickup in the distributer sends a spiked AC signal across terminals P & N of the module. approx +/- 3V?
2) The module converts this AC signal to a square wave, which outputs to the ECM via the "R" Reference Terminal.
3) When the ECM is controlling ignition advance, it sends a 5V? signal to the "B" bypass terminal of the Ignition Module.
4) The ECM then controls ignition advance by varying the pulse width duty cycle of the Square wave signal that it sends to Ignition Module terminal "E" EST.
My questions are as follows:
A) In regard the the SQ wave reference signal that the module sends to the ECM: Is it the leading or trailing edge of the signal that is the trigger point?
B) Does the EST signal Directly trigger the module, or does the module just measure the duty cycle of the EST signal and use that figure to calculate the required advance from the reluctor trigger point? If the EST directly triggers the firing of the module, is it on the leading or trailing edge of the variable duty cycle square wave?