DFI open/closed loop problems

Andris Skulte askulte at emerald.tufts.edu
Mon Apr 6 03:52:20 GMT 1998


Bruce Plecan wrote:
> 
> >From what I've got programmed, it should be in closed loop above 100
> >degrees coolant,
> 
> Sure it's F, and not C?

Pretty sure, since the default is 140, and that is kinda hot in C for
coolant :)

> Does the O2 need to swing for it to look awake to the ecm.  ie, it's
> so rich, that it doesn't "look" right to the ecm.  Were ya using a 1.8
> msec base pulse?.  Might try way down like 1.5, just a guess.

DFI doesn't have a base pulse feature. The fuel map is rpm vs MAP, and
the values are pulsewidths. At the 1 bar row, the values go from
7.7ms at 400rpm, peak at 9.15 at 4000, and go back down to 8.5 at 5200. DFI lets
you reduce the value of the whole map by a certain percentage, and I
tried 93%(7% reduction) to see if there was an 02 change (wasn't). I'm
leery of leaning it out too much, since I'm afraid of detonation and
blowing up the motor... I'll hood up the DIY_EFI o2meter onto it as soon
as I build another one (first one croaked after a cold spell) FWIW, I'm
running 30# injectors, on a 320hp (350 w/ SR intake maybe) V8 motor and
batch fire speed density injection. I can email DFI files to anyone that
is interested, or can help. Thanks again :) 

Andris



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