OK I've read the articles etc and come to the conclusion that the ref signal isnt needed/used if you were to go stand alone.
And if I've read it right you get a 5V pulse when cylinder 1 and again when cylinder 2 fires (obv the only way to truely test that is the go to sequential fuelling and see if you get power or flames lol).
I love OEM ECU's :d
"
In-cylinder pressures affect spark
plug breakdown voltage levels and the
timing of the breakover events. Under
certain engine operating conditions, the
in-cylinder pressures for the waste
spark ignition running mates can be
nearly equal. During deceleration, the
pressure of the compressing cylinder
can be as low as or lower than that of
the cylinder on its waste stroke. This
condition would, of course, render the
CSI signal information invalid. For this
reason, the PCM considers the
CAMOUT signal valid only during certain
MAP sensor ranges."
