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XfireZ51 · 08-31-2014

Here's another explanation of why people may have done this early on. And it's for the same reason the GN guys would disconnect the BATT just before a 1/4 run. If you are running Closed Loop, the ECM uses the last BLM value before the system goes PE (power enrichment) for WOT. All fueling is based on the VE table, whether Open or Closed Loop. If the last BLM THE ECM saw before PE was above 128, the ECM adds fuel to the calibration beyond what would be calculated using the PE table. IOW, it richens it up more. Even tho you may have tuned WOT, THE ECM overrides that because the motor is running leaner than it should. A precaution against running lean at WOT. THE GN guys, by disconnecting the BATT, would reset the BLMs to 128 and so the ECM would not
change the WOT tune.
Pulling the hose on the VAFPR, richens the mixture in C/L bringing the BLMs down to 128 or below. ECM leaves things alone at least for a long enough time to get a run in.

08-31-2014	#7
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,686	Re: Fuel Pressure Reg. ? Here's another explanation of why people may have done this early on. And it's for the same reason the GN guys would disconnect the BATT just before a 1/4 run. If you are running Closed Loop, the ECM uses the last BLM value before the system goes PE (power enrichment) for WOT. All fueling is based on the VE table, whether Open or Closed Loop. If the last BLM THE ECM saw before PE was above 128, the ECM adds fuel to the calibration beyond what would be calculated using the PE table. IOW, it richens it up more. Even tho you may have tuned WOT, THE ECM overrides that because the motor is running leaner than it should. A precaution against running lean at WOT. THE GN guys, by disconnecting the BATT, would reset the BLMs to 128 and so the ECM would not change the WOT tune. Pulling the hose on the VAFPR, richens the mixture in C/L bringing the BLMs down to 128 or below. ECM leaves things alone at least for a long enough time to get a run in.