Injector duty cycle PID???

[SideStep]

For give the simple question :

I used the forum search function and could not find it. Where do I find the injector duty cycle PID in the VCM Scanner???

Thanks,

[jimmyblue]

You may have to work with the injector pulse width
and calculate it up (using RPM)?

[SideStep]

You may have to work with the injector pulse width
and calculate it up (using RPM)?

OK, do u know what the formula is???

[jimmyblue]

I believe it's

PW(msec)*RPM/1200 = Duty Cycle (%).

http://www.ecanfix.com/~mdhamilton/dutycycle1.html

I got this info off a LS1Tech.com thread.

[SideStep]

I believe it's

PW(msec)*RPM/1200 = Duty Cycle (%).

http://www.ecanfix.com/~mdhamilton/dutycycle1.html

I got this info off a LS1Tech.com thread.

Cool, thanks
I did a little research and it looks like that is it.

Now if I can find out why my 42lb injectors (48.5 at 58psi) are running at and over 100% duty cycle at WOT above 5800rpms???

[jimmyblue]

One thing is to make sure that there is not a big
round-off (round-up) error. With that fat of an
injector you shouldn't need 100% unless you are
a big-HP motor, probably boosted. Also I have a
vague recollection of people mentioning that the
PW may have some inaccuracy to it, as reported
(generically) but I don't have anything specific there.

It may also be possible that there is something about
the commanded AFR, PE, the IFR and maybe other stuff
that is telling it to max out; what does your O2 /
wideband info tell you about whether 100% is over-
rich, or falling short? I think the stock calibration data
may be "fighting" fuel system shortcomings with
kooky high PE-vs-RPM that might want to be peeled
back for big injectors and solid plumbing.