ZR-1 Net Registry Forums - View Single Post - For tuners, a Holy Grail of Injector voltage Offset

XfireZ51 · 04-25-2014

Thought I'd resurrect this now that I have had a chance to try the new offset values for the Accels and do some logging/tuning. Been able to do a few runs. Came as no surprise that the initial run showed BLMs being rich. I datalogged the last one after doing a "global"reduction of fuel.The lower rpm/kPa region is still rich, particularly decel, but cruise and idle areas are coming in nicely. One observation is that the BLMs on both banks are much closer together. There still is a "split" but the variation on left to right banks is now within 7-10 counts instead of 20, ie 133-125. Still getting a few areas where the injectors just seem to shut off and where the ECM falls out of closed loop. I suspect that the O2 voltage is moving somewhere below and above the O2 C/L window settings. Usually w a blip of the throttle it jumps back into C/L and Learn. I am thinking I'll leave this alone and see if it doesn't work itself out as I get closer to good tune.
What's also interesting is how much steadier the BLMs are and how much more quickly you get to a pretty decent tune level. Finally, I suspect that with a more accurate injector PW calc, my MPG will probably improve. I could see it in the Instant MPG as I was driving this last time.

04-25-2014	#54
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,685	Re: For tuners, a Holy Grail of Injector voltage Offset Thought I'd resurrect this now that I have had a chance to try the new offset values for the Accels and do some logging/tuning. Been able to do a few runs. Came as no surprise that the initial run showed BLMs being rich. I datalogged the last one after doing a "global"reduction of fuel.The lower rpm/kPa region is still rich, particularly decel, but cruise and idle areas are coming in nicely. One observation is that the BLMs on both banks are much closer together. There still is a "split" but the variation on left to right banks is now within 7-10 counts instead of 20, ie 133-125. Still getting a few areas where the injectors just seem to shut off and where the ECM falls out of closed loop. I suspect that the O2 voltage is moving somewhere below and above the O2 C/L window settings. Usually w a blip of the throttle it jumps back into C/L and Learn. I am thinking I'll leave this alone and see if it doesn't work itself out as I get closer to good tune. What's also interesting is how much steadier the BLMs are and how much more quickly you get to a pretty decent tune level. Finally, I suspect that with a more accurate injector PW calc, my MPG will probably improve. I could see it in the Instant MPG as I was driving this last time.