It has been my experience with the
EC-2, the coils will stop firing when the battery
cranking voltage drops to a certain voltage. This isn't
too hard to do when cranking a new engine. Does anyone know precisely
what that voltage level is where the coils will no longer fire the plugs?
Don’t know exactly, but I have
found that the spark is weak (jumps maybe 1/8 - ¼”) while cranking the 20B
with the starter, when the voltage was pulled down to about 9.5 – 10. Using
the ignition test mode at 12 volts the spark will easily jump an inch gap.
Prior to the addition of voltage compensation
to the EC2 injector pulse width, I’d notice the engine starting to run
rough when the voltage was down to 11v. Now it is not so sensitive.
It might be an interesting test –
run with the field breaker pulled until the engine begins to give up, and see
what the EM2 voltage reads. Won’t be able to tell whether it is the
ignition, injectors, computer, or what. My voltage regulator keeps the voltage
at the high end of the range; about 14.75 when the engine in running; so things
are tuned to that point. Things may get out of tune a bit sooner following an alternator
failure than if it was lower.
Al G