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Old 10-30-2022, 01:26 AM   #1
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Flex Fuel Gauge only reading while idling

Recently my flex fuel gauge has been playing up, it was working for an entire year previous to this.

The only thing I can think of that may have caused it was I was driving around looking for e85 and may have run the tank all the way to the bottom line of the petrol gauge before I filled up.

Lately 5 sec after start up there is some hesitation of a second and also randomly there is like a brief timing pull? (not sure but it burbles and pops a little and hesitates).

I also thought it could be dirty fuel, but I refilled half the tank with some premium 98ron from Shell (best available petrol in OZ) but it still has the same issue.

So basically when the car is idling it reads the flex fine:
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But then when the car revs (past around 2k rpm), it doesn't show anymore:
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When the revs drop and it *resets* it goes like this:
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Before eventually reading the ethanol content again

Has anyone else encountered this before?
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Old 10-30-2022, 01:48 PM   #2
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I`m sure mine reads constant. If the sensor is faulty it could be giving bad readings to the ecu. If its the display it probably wont matter. i dont know what sensor to read on the ecu. With the torque obd2 app its not ethanol content.
Maybe in here
Wait until my Flex capacitor hits 88

Last edited by gen3v8; 10-30-2022 at 02:08 PM.
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Old 10-30-2022, 04:09 PM   #3
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The diagram @gen3v8 posted the FF sensor output is the green wire. It's a 0-5vdc output. Check the voltage output and see if it is dropping out with revs or holding steady. Not knowing the scaling for the ethenol compensation table can't tell you what voltage should be for your ethenol content but it should be a pretty steady output. Though according to the pdf it should be about 2.2vdc.
"Experience is the hardest kind of teacher. It gives you the test first and the lesson afterward." -Oscar Wilde.

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Old 10-31-2022, 07:25 PM   #4
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Ah bloody silly of me. I was playing around with the manifold and forgot to tighten down the grounding bolt that is off the connection to the O2 sensor for FF...all is working as per normal again.

Thanks gents
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