My Futurlec order still hasn't arrived after three weeks so I've just reordered the components from Mouser. They should be here next week.

Went out to RadioShack to get a box to put the circuit board in to protect it. This is 3" x 1.5" x 1" and will fit neatly by the ECU.



I'm not sure of the best place to insert the FlexFuel sensor into the return line. The flex hose in the engine bay between FPR and hard return seems easy but I don't know if it drains out when the fuel pump is off. If it does drain, it would give a false reading on startup. Can anyone add their own experience of mounting it in this position?

More to follow when those components arrive.......

 

Subscribed for updates! Keep up the good work guys.

 

This is a great idea for the evo community. also where do I get FreeFuel_v1.1_patch.jdf, I only see .asm files.


~~Edit~~

Nevermind saw that the jdf was posted in second post.

 

240Z TwinTurbo Mounted his on the firewall in line with the return line. R/T Ernie was talking about moving his further back toward's the fuel pump.

 

Did you figure out if it drains out in that location?

 

Whoever is creating the rom should some how lock the ethanol content during wot like on AEM v2

 

It already has this; there is a load and RPM threshold to freeze the ethanol content value.

 

Nice!! I'm ready to test this for Evo 9!!

 

Looking good man. Way to take the baton.

In the code, we need to implement a simple reporting mechanism (which may/may not require deleting one that exists lol). Just a thought with no real scientific premise.

After a little bit (5 minutes) of research, I would probably have to redesign the circuit or create an isolating splitter to report voltage to the ECU and a gauge. I don't want to mess with the current model by probing it due to it's simplicity, functionality, and accuracy.

Edit: "isolating splitter" / OPAMP lol

 

I thought that MUT 83 will give the raw output from the frequency to voltage convertor, which can itself be converted to E% with a suitable scaling factor (see post #110).

 

A couple of questions from a curious mind.....

1. What convertor are you using - Zeitronix ECA?
2. What hex value have you got in your MUT table for 83?

 

ECM Link are experimenting with this. They are using the MAF input so no need for a frequency to voltage converter. I wonder how hard that is to code.

 

I meant blinking lights like while driving.

 

I got the circuit built and tested it with the sensor and some control fuel mixtures this weekend. Output voltages were a little higher then expected which I traced to an out of spec C1. It measured 10.4 nF , too far to the high end of the tolerance range. I found another capacitor which measured 9.8 nF, soldered it in, and it gave me the correct output range. I recalibrated using Air = E0 = 50Hz = 1.59V; E80 = 135Hz = 4.26V, and E100 = 158Hz = 4.98V. Here is the finished product.



Next up was to complete the loom for the sensor and finally the power and ground feed ready for installation next week. All set!

 

Definitely harder than building a frequency to voltage converter, bearing in mind the coding has already been done by ast in his ROM 9653E706, all be it for the Evo 8 only at this time.