My Quest of Running Flex Fuel on MS3+MS3x
#1
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My Quest of Running Flex Fuel on MS3+MS3x
<p>This has been touched upon recently in a couple other threads so I am going to make a central thread where I document my process of setting up flex fuel on my home built MS3+MS3x. The process should be quite similar on MS3Pro, and MSLabs MS3s. You peasants with MS2's I can't help you. The goal is that by the end of this I will have a shopping list that anyone can go purchase and run flex fuel with their megasquirt.</p><p>Parts I've acquired so far if you want to follow along:</p><p>GT500 600cc injectors</p><p>DW200 Fuel Pump</p><p>GM Flex Fuel sensor (there are multiple to choose from, see this link for more info about the current cheap ones)</p><p>Sensor Harness</p><p>Ricey Badge (Optional)</p><p>I have done quite a bit of reading, and have contacted DIY autotune for some base maps. As far as I can tell I'm going to wire the flex fuel sensor into the Flex Input on my MS3x and then that should give me ethanol percentage. Everything after that is going to be tuning, and I will figure that out in the future.</p><p>Two Miatas that I have seen mentioned running flex fuel are <span>@AbeFM and DIYs Miata, </span><span>@Matt Cramer and <span>@Ben, any input is greatly appreciated. Attached is the basemap that DIY sent me from their miata running flex fuel.</span></span></p><p> </p>
#14
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@Reverant could you clarify when it became a standard feature and what the wiring is to PE0?
99-00: 3.1 and higher
96-97: 3.1 and higher
94-95: 3.0a and higher
90-93: 3.0a and higher
The suggested modification above means that you will need to connect the 2 resistors to the sensor and the MS3 board as shown, then route the wire to the ECU through any unused pin on the DB37.
#20
How'd it go? I had lots of issues early on, something in the code would lose count, and it'd think my fuel temp was -40* C or something ridiculous. Anyway, it would go full rich to compensate just once in a while, whole car bucked. I complained, I assume some smoothing was done in software. Worth being aware of. :-)