When Pete says something, it pays to listen. He has worked on Moto Guzzis before.
Looking at your first post, it seems like pic 1 oscilloscope trace shows a lower sensor voltage and lower speed than pic 2.
The SENS813 is an inductive pickup, which would put out lower voltage pulses if the gap to the phonic wheel was large.
I think you could try reducing the SEN813 sensor gap to the minimum, and temporarily leave the o-ring seal out, just to check.
As I see it, the sequence of events in the ECU are:
1. ECU Power on, self test, sensor check, and pump prime.
2. The ECU then waits until SEN813 pulses reach a "run" threshold.
3. The ECU will then turn on coils and injectors as instructed by the BIN file program.
If the SEN813 sensor is faulty, or if the gap is too large, the ECU will not power the coils and injectors.
As Chuck mentioned, electrical connectors can cause problems, and it is a good idea to remove and clean the connector to the ECU.
What does your instrument panel RPM display show during cranking when it is sparking and not sparking?
Be aware too that your manual says "If in the wrong position, the bank angle sensor may lead to sudden engine stalling".
You mentioned this at the start, but you could try disconnecting it.
thanks marty.
Today I heard from the owner, car hit the parked MGS!
so reassembled the left engine head by ex-repair shop before.
and that the engine did not start after that.
If so, it would have been reassembled the timing belt.
Fortunately,the valve and the pistons are not contact.
there is strong doubt in timing belt assemble.
i want to reassemble timing belt, but the contents of the manual are not sufficient.
if there incorrect belt assemble,
Could there be a difficult section of the starter motor running?
(when Left piston do uprise, Right piston cause a pull?)
I agree If starter motor running slow, it could interfere with the operation of Sen8I3 as pete said.