O2 Sensor Bias

[Bruce Plecan]

-----Original Message-----
From: Greg Hermann <bearbvd at sni.net>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Thursday, August 27, 1998 9:28 PM
Subject: Re: O2 Sensor Bias


>>Excuse me, kind of new here. What's wrong with lowering fuel pressure to
lean
>>out the mixture "across the board" as you want.

OK so far.

 Since GM ECMs go into open
>>loop at wide open throttle (signaled by the throttle position sensor) the
best
>>way to lean it out, or richen it for that matter, is by changing the base
fuel
>>pressure.

Trouble is that it uses the learned corrections from closed loop, and
applies those to WOT.  Some say just the rich corrections, others
say either.

Lower the pressure until you get the O2 readings in the range you
>>want (800-850?). Unless your base fuel maps are way off or the injectors
are
>>sized wrong that should work, right?

Trouble is that just about any serious rework does exactly that.
And for some reason, some cars just like more/less fuel then
their twins.
Cheers
Bruce

>>greg kring
>>
>Nothing, as long as you don't screw up atomization of the fuel.
>
>Regards, Greg
>
>
>