When you first set the engine constants you put the inj flow (cc/lbs), how many injectors, how many cylinders, simultanous firing or bank fire, and a few other things then it will give you a quasi close fuel map. It was good enough to start the motor on. If you have a o2 sensor it has a closed loop mode but it will only work for one AFR, I turned that crap off and i'm using a software package that was designed to tune megasquirt, tuner studio. With that software i can make a a map of target AFR's and then just drive on the car and it will continously update the fuel map till i acheive my targets, but you got to have the laptop pluged in to do that. I've messed with different management systems and tuner studio is pretty slick but i had to buy the registered version...$40.
When I had my injectors cleaned I had the guy measure the flow rates at 30psi fuel pressure(thats what the stock fuel pressure regulator is set for), and 43.5psi(standard 3bar of pressure, thats what most injectors are rated at). I can do a little math and figure out flow rates at different pressures.
there were a few settings for the pulse width modulation that i had to adjust but everything was described in great detail in the megamanual. the megamanual takes you step by step through initial startup and tuning. i'm a little thick headed and just jumped in, probably why it took so long to start it up.
