Injectors are PWM or pulsewidth modulated. In the newer returnless cars, the fuel pump is also, but that is anotehr subject.

All that section says is that wile in closed loop (and this is key and probably where your confusion lies) feedback from the 02's are used to determine whether the car is running a stoichiometric a/f, or 14.64 (if this is what is commanded, which it is for a stock file and is usually no changed for an aftermarket file).

SO bascially the 02's ONLY tell the EEC isf the mixture is rich or lean from stoich, and only at closed loop. At WOT (which commands open loop) the EEC has no idea what the a/f is..and thecommanded a/f is much richer than 14.64...

Now if you artifically raise the volatge on the MAF, thenyou are doing two things: you are makignteh car run rich, as the EEC thinks it is seing more air than actual, and two is you are arificially fudging load calculations which will in turn result in load being calculated toohigh and timing being reduced in turn.

You must also take note on the fact that MAF input even affects how an automatic transmission feels while shifting.

Let me add some comments:

The air meter actually measures mass of air that is flowing into the engine. The EEC also knows the mass flow rate of the injectors. If you are flowing, for example, 20#/min of air into the motor, and want to run 14.64:1 air/fuel ratio (which happens to be the chemically correct a/f raito for heptane, basically gasoline). So with 20#/min of air and a desired a/f ratio of 14.64, you'd need 20/14.64, or 1.366#/min of fuel. Let's multiply this by 60 to get #/hr of fuel, so we need 1.366 times 60 or 81.97#/hr of fuel through all the injectors. If you had say 8 injectors, each injector would have to inject 81.97/6 or 13.66#/hr of fuel. With a 24# injector, this is 13.66/24 or 56.9% of full injector opening.

This part is straight forward. If you change air meter and don't tell the EEC, you will deliver the wrong amount of fuel, period.

But something else happens:

The EEC calculates what's called load, which is essentially volumetric efficiency or VE. VE is the efficiency of the engine to pump air. For a 3.0L engines, in two engine revolutions, you can move in and out 3.0L of air. If the engine only moves 1.5L of air, then it's VE is 1.5/3.0 or 50%. Since the EEC knows mass of air, air temp and barometric pressure, it knows the volume of air that is moving through the engine at all times, so it can calculate VE.

The spark and fuel tables are tables for the amount of spark to deliver and the a/f ratio to command if you are NOT open loop. Open loop is when you are richer than 14.64:1 a/f raito and no longer using the O2 sensors for feedback. This could also be called power enrichment, a throw back to the carb days. The spark and fuel tables have RPM on the X axis and load on the Y axis. The output is then spark or a/f ratio. If your air meter transfer function is off, this is the input voltage from the meter to the EEC and what the flow is at that voltage, you will calculate VE wrong and hence grab the wrong spark and fuel values from the table.

This is why the air meter transfer function is so critical to making the engine work right. VE gets an input into almost everything, even what the trans feels like when it is shifting as I said above.

Now, someone will say that you can get an air meter calibrated for a given size injector and not change the EEC. This is right and wrong. Let's say you have 19# injectors and some air meter. You want to put in 38# injectors. You send your air meter off what they do is TRY to make it so at every voltage point your reading out from the air meter is original injector size divided by new injector size, in this example, 19/38 or 1/2 of the original value. Now, the EEC thinks there is very little air flow into the engine. Let's say before at 2 volts it was 12#/min, now with the "new" air meter, to get that same 12#/min you are at 1 volt. So, you now running at 1 volt with 12#/min of air and the EEC thinks you are running much lower flow, thus giving you a lower fuel pulsewidth, in fact, if the air meter was set up right, you will have 1/2 the pulsewidth and the amount of fuel going into the engine will be correct.

This is the part that's right. Now the wrong part. Load is calculated incorrectly, in this example, it's 1/2 of what it should be. So, you grab the wrong values out of the spark and fuel tables. This typically ends up in knock on some cars, since you are leaner with more spark.

I hope that shines some light on this...