Flex Fuel Setup/Stock ECU

Hey guys,

I'm looking at using an ethanol content analyzer to set up flex on my Evo 8MR. I've had a bit of experience with this on my last Evo which used a Link G4+, so using the wiring diagram Link supplied it was quite easy to wire it in and set up on PCLink.

On my current Evo, which has a stock ECU that I don't plan on upgrading at this stage, I would also like to set it up for flex fuel using a Zeitronix ECA. I'm having a difficult time trying to understand how, or rather where to wire in the signal output from the ECA to the ECU (so that the ECU can control the map based on ethanol content).

I've had a look at the stock ECU wiring diagram though I can't seem to figure out what pin would be the correct one to use. Unsure if I'm looking at this from the wrong angle, and was hoping someone who has wired in a flex set up on a stock ECU would be able to assist.