Software version 0420

One further question.

What is the function and effect of the Trim2rich and Trim2lean buttons?

And to be absolutely clear - it is the Open loop rich and Open loop lean buttons that I use to adjust the fuelling isn’t it?

Ok that's two questions :whistle:

The openloop rich and lean are sending commands to the ECU which are the same ones that a T4 would send.

The trim2 method is one that someone else reverse engineered out of an ECU by sending 255 different commands and seeing what would happen.

If you increase trim2 it seems to also increase openloop and if you increase openloop it seems to increase trim2, so it appears to be a second way of adjusting the same thing.

I probably should just remove the buttons as they seem a bit redundant and I guess that no one is going to risk trying them.

Phillip

Thanks for the explanation!

I'd probably change the labels on those buttons (if there is space) to "Open loop fuel enrich" and "Open loop fuel lean"

Philip, I forgot about the Trim2 buttons - we should have tried these on Saturday! D'oh!

Hi Philip,

reviving this old topic as I am about to start a little project involving my 1972 Midget and a classic Mini SPi manifold. As you know, the Mini uses a MEMS 1.6 ECU (MNE101040, which I still have to find, rare as the proverbial hens’ teeth). From what I learned so far, the 1.6 and 1.9 versions are quite similar. Do you think the tuning functionalities could be enabled for the SPi setup as well?

Kind regards,
Michael

it is possible to modify the parameters in the MEMS1.6, however it doesn't survive a power cycle. This doesn't seem that useful in the real world.

Now that is interesting, Philip, albeit a bit awkward. Do you know the reason for the different behaviour? Could it be the 1.9 units use a buffer battery to keep the memory intact?