Re: DFCO Questions.

[Ludis Langens <ludis@cruzers.com>]

Ross Myers wrote:
> 
> 1 - In the factory tune I think they don't cut the fuel off completely, the
> "DFCO MULTIPLIER STEP VALUE" is not set to $FF instead it is at $60, does
> this actually mean the fuel is not totally cut?, why would it be like this?.
> The V6's have it set to $FF.

The step of $60 means that the fuel will be cut in steps.  First to
159/256 of the full amount, then to 63/256, and finally fully cut.  Each
step is 1/80 of a second long.

I have a set of bins where manual transmission cars have an instant
DFCO, while automatics have an intermediate step of 50%.  Why - I dont know.

> 3 - In 5th gear (manual of course) at 80kmh the car sits at about 1400RPM
> going down hill, this RPM is still too low to enable fuel cut, so should I
> be worried about how low I set the min RPM for DFCO?, I was thinking around
> 1250 or so.

In the same set of bins I mentioned above, DFCO is allowed down to 1550
RPM.  This is on an engine that doesn't ever like running below 2000
RPM, and which idles at 950 RPM.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org