well if it was set up to run in closed loop, the computer would make NO adjustments to the fuel injection. closed loop is a fixed setting. when it is in open loop, that's when it (and you) will make adjustments to the fuel curve. for example, when you first start your car on a cold morning the computer runs in open loop so that it can get the air temp, exhaust temp and all that, to adjust the fuel curve to make the engine run right.
once the engine is warmed up, it switches to closed loop. this is how and why fuel injection does not require a choke like a carb does.
also, if you add nitrous to a f.i. motor, the computer WILL NOT automatically add more fuel. if you add nitrous to a f.i. motor, you have to increase the size of the injectors, and add a secondary fuel line to add more fuel when the nitrous is activated. this second fuel line would be tapped into the return fuel line and would be hooked to a solenoid. when you push the nitrous button a nitrous solenoid and the seconadry fuel solenoid are activated, spraying both the nitrous and the fuel from the return line into the intake under pressure. the more nitrous you use, the more fuel you need to add. i think that the kits for these 2 stroke engines add a small enough amount of nitrous that you could get away with just running the carb a little rich to compensate for the extra fuel needed. i don't see you having to run a secondary fuel source into the carb. for the nitrous. now when you are talking a 200 horsepower nitrous set up, then it is crucial to add more fuel. the other thing about nitrous is that you actually need to retard the ignition timing 2-4 degrees and run a colder plug to make it most effective.
this is how it works on a 4 stroke v-8 anyway.
one thing taht got me wondering....aren't there some weedeater out right now that are 2 strokes with f.i. ?
if there is, one of those set ups would be the way to go.
if there are f.i. weedeaters, i can imagine that they are probably mechanical f.i. and don't need a computer. but the injector size may be too small, and they may not give enough fuel to an 80 c.c. motor. most weedeaters are 30-35 c.c.'s and running too small of an injector would make the motor run too lean.
just a thought.