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Old 09-30-2017, 03:52 PM   #15 (permalink)
gpfaster
EcoModding Lurker
 
Join Date: Sep 2017
Location: Hamilton, Ontario, Canada
Posts: 19

Saturn - '01 Saturn SC1
90 day: 42.33 mpg (US)
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Quote:
Originally Posted by MetroMPG View Post
Another consideration: how is the app determining you're in DFCO? An OBD-II device doesn't have access to actual fuel injection metrics. So it's inferring DFCO either from user-settable throttle position + RPM settings or possibly from open/closed loop status, or a combination of both.
I am gauging this by fuel flow readings, which never drop to 0/lph unless I kill the engine. Another question is if the app is measuring pump flow or actual delivery to (at) the injectors. So my previous assumptions, on dfco vs neutral coast may be wrong..

When this car is in neutral coast it holds the idle at ECU commanded 1100 rpm +- to help rev matching??. Where as when i am asking for dfco it's running off my input via throttle position sensor.. I do see the difference on fuel consumption in these two scenarios..

Neutral idle won't drop down to 750rpm until ECU detects 0 speed from the VSS..

I'll grab some screen shots and try some data logging a little later.. Going to pick up my sister and I have a looong 5km + downhill coast with a 70km/h limit

Good discussion, I appreciate it, I'm enjoying this little challenge!
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