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1994 Toyota Supra Turbo 6spd
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Discussion Starter #1
i have my cruise A/F ratio set at between 13-15 a/f and idle around 13-15 a/f as well.

but i am getting horrible gas mileage, about 10-12 mpg even if i drive real easy and cruise.

is there anything else that i am missing that can contribute to the low gas mileage? only thing i can think of is that my gas tank isn't sealed 100% because i had to cut a small hole for the fuel pump wires to come through.. then i sealed it with silicone sealer but i know that didn't seal it 100%
 

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1994 Toyota Supra Turbo 6spd
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Discussion Starter #4
well i'm not a certified tuner but i am tuning it right now and it does run decently.. just the MPG is really bad!!!

if the a/f ratio was more rich at cruise and idle i can understand that but it seems to be perfect!?
 

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33truballa33 said:
are u tuned? i kno most ppl keep their a/f around 11 when driving

lol, fucking unreal :), those most people you know-are they your age and younger? did they finish high-school?? lol, do they use Motec Exhaust to get 11 a/f when driving?? Rob NJ.
 

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well assuming "cruise" to you means light throttle going 60mph.... it has nothing to do w/ your tune if your on stock ecu because your ecu will try to override any fuel trim change. did you consider your stock O2 is going back? a sure-tell sign of it is ur mpg decrease. also if u have a narrow band AF gauge, see if it bounces around in cruise/idle. if it looks "lazy" then thats ur stock o2 dieing. do u also use alot of race gas? that will kill the o2 even quicker.
 

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1994 Toyota Supra Turbo 6spd
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Discussion Starter #7
mifesto said:
well assuming "cruise" to you means light throttle going 60mph.... it has nothing to do w/ your tune if your on stock ecu because your ecu will try to override any fuel trim change. did you consider your stock O2 is going back? a sure-tell sign of it is ur mpg decrease. also if u have a narrow band AF gauge, see if it bounces around in cruise/idle. if it looks "lazy" then thats ur stock o2 dieing. do u also use alot of race gas? that will kill the o2 even quicker.

i have an aem and i hardly run race gas, if 100 sometime... i plan on running C16 soon but i haven't yet. my 02 sensor seems like it's okay. i don't have any stock 02 sensor anymore (because of aem). the cruise is real good actually, any gear and mph if i am going 4000 rpm or under light throttle, it's perfect 13- 15's..
 

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Did you set the 02 wizard correctly and set the O2 gain the way you are supposed to? Did you set the EMS to feedback on the correct cylinders per 02 sensor? Remember if you are putting the sensor input into the front O2 sensor connector near the front turbo, that is sensor #2 for the Supra. Just gotta make sure the basics are covered here....

You should be running about 40-45 deg timing at cruise as well.
 
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