DIYEFI.org Forum

If you have a seemingly noisy RPM signal in your logs, ensure that your rev limiter hysteresis is greater than the variance in your RPM. If not, it will cut in and out too quickly potentially causing harm.

I noticed this while viewing a log of Sim's and spotted his fuel cut limiter in action at the end of most gears. Of course, he has no injection, so no big deal, but the same would happen at higher RPM for ignition. In that particular case, it could be a good thing, but for injection it's a bad thing.

Fred.

On the slow ramp up side (slow in the snot rocket, anyway), there is time for it to oscillate in and out of cut. Obviously if it was cutting it would fall more violently and thus be less eratic, but it'd still not be ideal. The down side is faster so doesn't experience this "sitting on an edge" effect.