I recently added a FF sensor to my car and am working on it now. I don't have LSA injectors yet, so I have not added more spark. Here are the changes I made in the tune. Before you get to this point, the FF sensor needs to be installed and the output wire connected to the correct pin on the ECM. For my E38, it is pin #40.
Engine > Fuel > Flex Fuel
[ECM] 201 Flex Fuel: Enabled
[ECM] 20220 Fuel Sensor: Sensor
[ECM] 3145 Default Frequency: 60 Hz
- This field is used if the sensor ever fails: 50 Hz = 0%E; 60 Hz = 10%E; 70 Hz = 20%E; ...; 150 Hz = 100%E
- I'd rather it fail to 10% and pull timing and have the fueling be rich, than default it to a higher E value, making the engine run leaner and with more advance.
[ECM] 3133 Maximum Ethanol Percentage: 100%
[ECM] 3146 Comp Change Thresh: 1%
[ECM] 3147 Delay Volume: .05 liters
[ECM] 3148 Transition Volume: .05 liters
Engine > Fuel > Power Enrich
[ECM] 12403 EQ Ratio (Alcohol): Set this table to the same as the regular gasoline (
although bit leaner)
Engine > Fuel > General
[ECM] 12560 AFR Term: edit the final column (percentages), stock the final column is 80%, you should change to 70% since there is little benefit to running any more than E70
Engine > Spark > Advance
[ECM] 12678 Flex Fuel: this is the
danger table!
- Zero out this table to start with. Drive around with the existing fuel to make sure your sensor is good to go and no leaks are happening. From there, start add one degree at a time to the .52 and higher rows and interpolate down to the .28 row. Ultimately this table will be the final part of your tuning with E85. I am not sure what the final total timing is safe for on the LSA engine.
[ECM] 12636 Mult vs Composition: (note: final column should be 70%)
.0%: 0.0
10%: 0.0
20%: .20
50%: .50
70%: 1.0
[ECM] 12663 Alcohol Mult: (note: final column should be 70%)
.0%: .000
10%: .125
20%: .250
50%: .625
70%: 1.00
Engine Diag > DTC (some these may not be available on your platform, you may have others, I suggest enabling anything flex fuel related)
P0169: SES enable & 1-MIL on Second Error
P0178: SES enable & 1-MIL on Second Error
P0179: SES enable & 1-MIL on Second Error
Engine Diagnostics > Airflow > Flex Fuel
Note there may be other options to enable in here if your platform supports it. Enable if possible.