[Gmecm] V6-60 DIS spark retard advice?

[Robin Handley]

My experience is with a dizzy trigger, but I don't think this affects the
answers to your questions.

> 1.  I have no VSS yet.  Does spark retard require VSS?

You didn't mention which code you are using but, from what I've seen, some
GM code (at least) doesn't require VSS. Also, GM seem to put code in there
to ignore VSS based checks if the VSS isn't present or is faulty - which is
quite handy.

> 3.  Assuming I have no other problems, how many
> degrees of retard can the DIS command?

Isn't the advance/retard under the control of the ECM code? Have you looked
for a lookup value which specifies maximum retard?

> 4.  I've tried to test the whole thing by hooking up a
> timing light, tapping the block with a hammer in the
> vicinity of the sensor, and watching the timing mark
> for movement (retard). I didn't see anything, but my
> sensor is now located near the starter (like on the
> 'Vette), and it's hard to whack there!  How close to
> the sensor should I have to hit, or does the sound
> propogate pretty freely, even past internal structures
> (main bearing saddles etc)?  Is it likely I can tap
> the block and produce the right frequency vibration to
> trigger retard?

AIUI knock sensing involves signal processing and may well not be fooled by
a few hammer taps. I was also advised that each engine has different noise
characteristics so not to expect a sensor and/or code from one engine to
work on another.

If you're hearing pinking/knock under particular load/speed conditions, have
you tried reducing the main SA lookup table in that area?

HTH

Robin