Dialing in fuel film

[pwrjet]

I have the acceleration working decently, I still see a short lean spike and then rich but the motor feels good so I think I'll leave it. It doesn't seem like there's really a way to remove both, I can get the lean spike smaller but then it will go even richer.

Now, deceleration I have not tried to setup yet but looking at the logs I'm not quite sure how to go about it. It goes rich first and then very lean for long enough that the RPM drops below idle temporarily. If I reduce "fast decrease time constant", if I understand this correctly, it would reduce fuel faster which would remove the initial rich spike but the lean spike is just 0.3s after that so that would probably get even worse?

What's the correct approach to correct his? Attached is a screen shot.

[Stephen Dean]

Hi,

I tune fuel film based on how the engine feels and drives in transient behaviours, this may not always result in having a "ideal" lambda trace to get working.

With the over run behaviour, this looks like the Engine Overrun may need some tuning. The area that is going lean is outside of where the Fuel Film would normally be active.

[pwrjet]

Overrun is not enabled.

When would the fuel film decrease fast and slow apply exactly? The massive lean spike happens a fraction of a second after the throttle is fully closed. I can probably make this better using the VE table, the lean spike corresponds to increase in vacuum, it goes below normal idle vacuum. I would prefer using fuel film to correct this if its possible.