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Old 12-10-2018, 02:55 PM   #224 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,527

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
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It works... but does it work?

So the switch/potentiometer on the coolant temp sensor works as expected!



But does it actually DO anything useful in terms of MPG?

I monitored fuel consumption (GPH) using this method on a cold engine:

- Starting FWT = ~35 F
- holding engine RPM steady at 2k RPM
- check GPH value
- activate mod so FWT value is ~160 F
- check GPH value
- toggle the mod on/off several times

From what I could see, there was no change in the GPH reading.

I was talking to Tim about this. I forgot that the ScanGauge doesn't read fuel consumption directly from injector pulses. It's estimating it from air consumption. And if I keep the RPM steady, the air consumption isn't changing.

So really I needed to be using an MPGuino for the test.

It's definitely having some effect: if I let the (cold) engine go to idle when the mod is switched on (spoof the computer to think it's warm), it stumbles and dies. The mod cancels fuel enrichment (how much??) and fast idle.
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Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
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Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



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www.MetroMPG.com - fuel efficiency info for Geo Metro owners
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