CrazyCab

but is the increase in velocity now causing the o-ring to actually block air from moving across the MAF wires? Full rich = not enough air and too much fuel or just not enough air.

VAP

for too much air with more fuel/voltage output, too little air by reducing fuel/voltage output.

Look at an o-ring as adding a small orifice to the end of your garden hose. A MAF only measures flow, hence the "F" in MAF = Mass Air Flow. A restrictor in the end of your garden hose increases velocity/flow but reduces volume. Since MAF cant interpolate volume it sees the additional velocity (flow) as increased air and richens to compensate. No air or too little air would starve the car for fuel and it would simply stumble/die rather than maintain idle or any speed relative to the air, or lack thereof, moving across the sensor wires.

An o-ring is simply a very small velocity stack, ie; it compresses a larger column of air into a smaller/faster column of air and speeds it across the sensor wires "faster" than the air going around the sensor.

And as my original post states I didnt rely on suspicion, intuition or conjecture as to if the MAF sensor was running lean/rich. I used a multimeter, a Fluke 88 AutoMeter. MAF sensor has a range of 1.5 to 3.4 volts from idle to 4k RPMs. The higher the voltage, the richer the fuel. All o-ring equipped sensors with flowtubes installed spiked 4.6- 4.8 volts at about 1,600-1,800 RPMs indicating a dead rich condition... FAR too rich for any RPM in the 12V. Without any o-rings in place voltage outputs came back into 1.6-3.5 volt outputs which is as near-perfect as is attainable.

CrazyCab

Ahh, I see

froisinator10

Is the stock maf 2.75 and tb 2.75?

MFZERO

awesome!