EFIDynoTuning Forum

Is it possible to add a flex fuel sensor to a RZASA ECU to be able to run E85 or other fuel octanes?

Anythings possible. Ethanol sensor measures ethanol not octane though.

Wasn't there a lincoln that actually had an E85 sensor (continental maybe)? I think everything after that used an inferred value to calculate ethanol content

Ha yep confused my terminology. Ok so it may be possible to install a flex fuel sensor to automatically adjust tune for e85.

I'm sure the tune isn't currently designed for this but would be a cool feature.

What pins would you recommend using? I can at least get a plug added to the harness for potential future use.

pin 31 is the power steering pressure sensor input would be most ideal

Do you have a recommended ethanol sensor? Thinking this could be a cool winter project.

i do not

Decipha
I believe the sensor was pioneered by GM, and duplicated by AEM and Haltec.
It seems to be a tube that gets spliced into the fuel line with a laser beam and
photo cell inside the darkness of the fuel changes the signal. Some are frequency based
So would need a digital? Input in the pcm.

Eflex.com or something similar makes a piggy back computer that splices itself in the harness at the injectors. It uses a table in addition to stock from 0% to 80% very linear increase in fuel and timing.

This additional table feature would be an awesome decipha programming addition to RZASA for e85 for boosted vehicles in the northern states.
ethanol dosent want to vaporize
Below 50 deg so they add preimum to it during the winter months so the cars will start (october through April it is
Cold in Minnesota). It can be as low as e50 though most of the time it is e70.
They do switch back to e85 in the summer but if the gas station dosent have many flex fuel customers it can take a while to get back to e85. Without a sensor you never know what your running

usually i open up adaptives and let it learn the trim then apply the correction to stoich. Spark doesn't change but e50 to e85 would have minimal impact on knock for the majority of engines.

a digital input would be more work an analog one would be most easiest. Not a deal breaker though.

will be a while before i get any free time to tinker any.

BTW, my closed loop wideband code infers ethanol that I was working on. Wouldn't even need a ethanol sensor.

Johnnyfast wrote: ↑2023 Oct 26, 02:41 Decipha
I believe the sensor was pioneered by GM, and duplicated by AEM and Haltec.
It seems to be a tube that gets spliced into the fuel line with a laser beam and
photo cell inside the darkness of the fuel changes the signal. Some are frequency based
So would need a digital? Input in the pcm.

Just looked up sensors, yea they are digital frequency output. I was assuming they were voltage analog output. Bummer.

I'll have to look if I'm using all the speed inputs.