battery voltage correction

[Moonsteel]

Can someone explain this to me, what it's used for and when it should be changed from .1

Thanks,

Jerome

[efahl]

On Tue, December 7, 2004 10:48 am, Moonsteel said:
> Can someone explain this to me, what it's used for and when it should be
> changed from .1

Jerome,

The injector opening time is significantly affected by the voltage
supplied to it. During cold cranking with a weak battery, you might
only see 8 v at the injector, but while running with a good charging
system you might see 14.1 v. So, what this parameter says is that
if your nominal injector opening is 1.1 ms at 13.2 v, then for every
change in 1 volt from this baseline, increase or decrease the opening
time in an inverse linear fashion...

BatV Opening time
11.2 1.3
12.2 1.2
13.2 1.1
14.2 1.0

(And this is the sole reason MS actually measures battery voltage.)

One shortcoming in the base MS code is that the cranking pulsewidth
does not take this into account, it uses a PW fixed wrt voltage
(varying only wrt coolant temp). Bruce has mentioned reworking this
in the past, but no one has ever gotten around tuit.

You should never need to change this, unless you have specs for
the injector that indicate a different rate.

Eric

--
Eric Fahlgren http://www.not2fast.com/

[Moonsteel]

Thanks.
I'm on a quest to better understand the settings of the MS, especially since it's getting colder and colder around here.