MicroSquirt.com read only forum (Jan.15,2018)

First off, I would like to say that I have read through the entire megasquirt manual several times, and I would like to thank everyone in advance for their help. I have a couple of questions that I have not been able to find answers for.

First off, on the red/green O2 gauge on the bottom of MegaTune's start page, is the red rich or lean? My guess has been that it is rich, but any clarification would be appreciated.

Second, my O2 reading has been staying around .8-.9 volts all the time, no matter what I do to the amount of fuel going through the injectors. The only time the red/green gauge goes anywhere near green is under full throttle conditions, when it goes almost all the way down to nothing. I don't fully understand what is going on there.

My last question is about the VE table. I am not really sure what I should be doing with it, if anything at all. The car starts, warms up, and idles perfectly, every time, and even feels and sounds great when accelerating. I am just not sure what I am doing when it comes to adjusting the VE table. Thanks for any help again.

1. Please note in your post if you are using MS-II/MS-I/MSnS-E, the code version, MegaTune version, as well as V1.01, V2.2 or V3 main board, etc.

2. engine details

3. 14.7:1 afr = stoich = proper chemical combustion
less than that (i.e. 10:1) = rich = bit more fuel and normal , engine should be slightly rich in high load areas (12.5:1 for NA and richer for turbo engines) for best power.

more than that (i.e. 16:1) = lean = less fuel than normal. in cruise/coast/low load areas depending on the engine type you should run as lean as you can for fuel economy. running to lean in high load areas is damaging to the engine.

where did you get your ve table that works that great ? did you just generated one ? you might got lucky that it work good for you.

tuning ve table - by adjusting values in the table you adjust afr for particular points. tuning manual describes well what afr's should be run in what conditions, so you should understand it by now and make sure you get desired AFR's at all rpm/map bins.

well, to answer your question, Im pretty sure green is rich and red is lean.
Sounds like its setup pretty good, rich during accel and lean during cruise, just dont let it get too lean. AC

If you are running MSII, did you remember to calibrate your AFR?

I am running a megasquirt 1, am not sure what version megatune I have.
It's a chevy 350, pretty much stock with a 2 injector TB. I am using the default VE table in megatune. I understand what rich and lean are, I just want to know where each is on the O2 gauge in Megatune. And I understand air fuel ratios, I just don't understand how I am supposed to adjust the VE table. When I take it out to drive it, I turn on the "tuning" page in Megatune and watch the VE on the little graph. It kinda jumps all over the place, but generally increases the way it should, until deccelerating, then it drops way down to like less than 20 MAP units, while the RPMs drop. By the way, it idles at around 30 Map units.

The map dropps while decel. because the throttle blades shut while the engine is still at a higher rpm. Its OK, they can drop pretty low but will rise to pressures seen at idle as soon as the rpm drops. My fav way to adjust the ve's is on the graph, using the arrow keys move the red x to where you want it on the graph, then hold the shift key and press up or dwn to increase or decrease the ve on that bin! and if your o2 sensor works you can turn on auto tune under tools on the ve graph page, but you will need to set up the ego controle under settings.