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Old 03-29-2014, 09:17 PM   #29 (permalink)
Join Date: Oct 2009
Location: South Central AK
Posts: 933

escort - '99 ford escort sport
90 day: 42.38 mpg (US)

scoobaru - '02 Subaru Forester s
90 day: 28.65 mpg (US)
Thanks: 32
Thanked 146 Times in 97 Posts
Is your data logger recording what scangauge reports as fuel consumption or actual injector operation?

Any news on getting an mpguino (or other direct injector duty cycle monitoring) into the mix?

As I understand most OBD fuel monitoring is based on airflow. With foot off throttle and open loop once up to temp = fuel off. If there is some parameters at low RPM that result in open loop operation with the foot off the throttle it could be tainting the results. (would be interested to have that misconception cleared up if I am incorrect)

This find seems almost too good to be true. I have noted that my ultragauge reports 999999 for a, um, noticeable, period of time after the engine rpm has stopped dropping and is idling (indicating that unaccounted for fuel may be being burned). I still think it's a possibility that indirect calculation of fuel consumption lends itself to the possibility of this being an artifact.

Your data definitely indicates that further investigation is in order. A way to get comparatively close to EO(ff)C performance out of engine idling coasting while keeping brake booster and power steering systems pumping is pretty awesome.

Could a signal to the solenoid that actuates the idle air control system automate this? I am guessing not as it seems to be linked to the throttle position sensor (which may be spoofable)

Ohh idea for another test. Monitor engine RPM, spoof the throttle position sensor and see if the ecu reports injector cut off.

not trying to criticize as I am really hoping this effect is workable.

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

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