Hey all, just a quick check to see if others see similar outputs as me. I've got an SoS sensor kit wired to an AEM Series 2 (Switch 2). I ran normal pump 93 as I tweaked the map for my swap from older ID1000 to ID1300x2 injectors, and had a consistent %E reading of 8%-9% as expected. I ran down to around 2 gallons left and filled up 9 gallons of pump E85. The result is showing around 53% ethanol, which tracks for the 9:2 fuel ratio assuming a 65% ethanol content in the pump E85 (which as we all know can vary in ethanol content).

What I noticed while logging on the higher %E is that my sensor has random quick blips/spikes in frequency. They're very short spikes (< 1 data point while logging) and appear to be random in occurrence, though the magnitude is consistent at +10Hz (+10%). I'm not familiar enough with the flow dynamics through the fuel return line off the pressure regulator, so I wanted to check with others if this is normal (e.g. random bubbles through the return line causing a measurement error) or if this is a problem and I should be concerned with the readings. Thanks!

 

Not normal flex content should be fully mixed and stable as soon as your car is full of gas it won't vary or change at all after that unless you fill with more fuel.

 

I had an unfortunate feeling that was the case. Since the raw Hz reading has those blips in magnitude that only last a few milliseconds, any ideas? I've got good power - aux connection from the fuse box under the steering column, and ground is one of the two main ground bolts. Guess I'll check the pin and make sure it's okay.

 

Aslong as your Flex content % is not changing sounds like shouldn't be an issue. Send me your log it'd be glad to take a look.

 

Maybe check the voltage when you see the spikes, could be some electrical interference.