[ShawnTaylor]

Is anyone running VSS and/or ETH (flexfuel) setups without any interferences/spikes ? I am currently running a V0.4.3 setup and I am noticing spikes and all sorts of incoherent readings, i.e ethanol content jumping from 75% to 30% ; similar issue with VSS, jumping from 50Km/h to 400Km/h etc. This is my second build, the previous build was fitted to my fathers Ford Sierra, he was having the same issue too. A friend of ours fitted an LM393 comparator IC and a low pass RC filter to help reduce the issue on my fathers car, but this setup has it's limits as the ETH % fluctuates at higher RPM. On the 0.4.3 board there are no hardware filters for VSS/ETH inputs and from what I've understood from looking at the firmware, there doesn't appear to be any software filtering either.

[stum]

Im running a V0.4.4 (sh board) purchased from the speedie store.

I have a Flex fuel sensor and it sits pritty stable, Only time it jumps about is when the tank is getting really low and im putting that down to air bubbles. Rest of the time no noticable change. I have run it from 0% ->70% ethanol.

[martysport]

Im running a V0.4.4 (sh board) purchased from the speedie store.

I have a Flex fuel sensor and it sits pritty stable, Only time it jumps about is when the tank is getting really low and im putting that down to air bubbles. Rest of the time no noticable change. I have run it from 0% ->70% ethanol.

Is yours on the feed or return pipe?

[stum]

Yes in the return line. Just before the tank.
Lower than the return point in the tank
Power and Earth from the speedie board adapter.
If you turn you fuel pump off is it stable. As it should continue to give a reading with no flow.
And what about pump on, motor not running. Should also be stable...... Those two tests should give you an indication if you are picking up electrical noise from some where, bad connection/sensor...........