[TELVM]

Originally Posted by Coyote X

Without a wideband it is pretty much impossible to get a good ve tune. If it was me I would just wait till I install the wideband and go to the megasquirt at that time.

Coyote is giving you very sound advice here Blownintegra.

Originally Posted by blownintegra

I have been trying to "guess" the size of the TBI injector, since this tidbit of info seems to be a mystery when searching all over the internet. I am sure that is a major issue with the fueling too. I will try to "tune" that in a bit. Trying to guess injector size is not fun.

In this thread they talk of 272 then 400 cc/min, no fuel pressure info:

Metro 3-cyl General Info - GasSavers.org - Helping You Save at the Pump

Being a 1 litre engine with ~55 HP, I'd guess the single injector should flow at least 260 cc/min. The '272' talked above may be correct. '400' seems oversize for the application, but could also be correct if Suzuki just used the same injector from the 4-cyl 1.3 in the 3-cyl 1.0 . Beware this is just speculation based on unreliable internet data.

The other thing is you can not open 2 windows of megatune to make comparisons of different tunes to try to put something together.

Yep. What I do to compare is opening one Megatune in my main PC and another one in the laptop.

Overall, I'm just happy that this thing actually works and is not just a gimmick!

Megasquirt can work superbly, but the learning curve is a bit steep at the beginning. Be patient.

So, to summarize, if I put "voltage" readings in, and make "adjustments" to the VE table, the computer will try to match the readings with the wide band?

You first create a more or less coherent VE table yourself by hand (the car starts and runs better or worse), watching by eye what AFR the wideband display shows you at each combination of kPa and rpm, and correcting by hand when neccesary.

Then if you want to use Autotune for fine tuning the VE table, you wire the wideband sensor to the Megasquirt ECU, adjust the EGO parameters in Megatune for your particular wideband model, and create a coherent AFR Targets table filled with voltages.

MSnS-Extra Software Manual

Then you run the car and activate Autotune. Autotune will look at the AFR Targets table for reference, compare on the run with what the wideband actually displays, and correct VE Table when neccesary.



An example: Let's say you've set a target of 15.0:1 AFR at 30 kPa & 3000 rpm in the AFR Targets table (expressed as, say, 2.5 volts). And previously you've set a value of, say, '66' in the 30 kPa/3000 rpm cell at the VE Table.

You start running with Autotune on, and Megasquirt detects (via wideband) that actually in the real world your engine at 30 kPa & 3000 rpm is running at 12.0:1 (way too rich). Autotune will start decreasing the value at the VE Table 30 KpA/3000 rpm cell: '66' => '65' => '64' ... and so on, until the wideband actually shows the target 15.0:1 AFR. The final value in the VE Table cell will be, say, '53'. VE Table cell corrected, job done.