[E4ODnut]

I'm not a great fan of closed loop control. First of all, it can be used as excuse for sloppy tuning. The other thing is that you are now depending on absolute accurate feed back from the wide band and I'm not convinced that this is realistic, at least not from my experience.

I use decel fuel cut a lot but I've modified the code and hardware so that I can do it manually. I've tried to lean out the mix during over run, but it seems to create more problems than it solves so I just use the fuel cut.

With the 4.9 I've found that I can run as lean as about 19:1 indicated before I get any lean surge but I keep it around 17:1 indicated up to about 80 KPA where I ramp up to about 12.5:1 at 100KPA. I've experimented with timing at these lean mixtures but haven't been able to really determine optimum. I'm not sure if there is a point of diminishing returns for lean mix. I just tune on the road, which is a bit limiting.

I am a great fan of MegaLogViewer. VE Analyze is nice, but I've found that even though it will get you into the ball park quickly I still end up studying the data logs and tweaking things manually. 1 or 2% in the VE table is sometimes all the tolerance you have.

I've built in a read out for fuel burn and found that economy is better for the same speed and load in a higher gear with higher manifold pressure, even if you end up with a richer mix. I think my read out is accurate to about 3% of actual, but even if it isn't the trends are what is most important.

Any idea what kind of accuracy the MPGuino can attain?