mass air flow voltage question

[silver]

Ok so I'm trying to tune my water injection, it connects to the yellow wire off the MAF.  Then you can change the brain of the system to start at any voltage between 2.0 and 4.5 volts, and reach max pressure between 2.0 and 4.5 volts.

Yesterday on my test drive I set the voltage to 2.8 volts and the water injection system never turned on...I thought I must have popped a fuse but as soon as I turned the dial back down below 2.5volts it turned on again.  So on to the attempt to tune.  As I'm sitting in my garage I have a volt meter hooked up to the MAF and it just sits there are 2.2 volts approx, it doesn't change on my volt meter even when I rev it...which is my question, is that normal or not normal?  what's the operating range in voltage of the MAF.

IF someone out there knows the answer this will help me tune my water injection system more accurately for example, if the operating voltage is 2.30 volts at idle and 2.8 volts at full boost, then I know that tuning my "max pressure" to anything over 2.8 volts isn't really effecting the system......so anyone know the answer?

[Terry Kennedy]

[quote="silver"]As I'm sitting in my garage I have a volt meter hooked up to the MAF and it just sits there are 2.2 volts approx, it doesn't change on my volt meter even when I rev it...which is my question, is that normal or not normal?  what's the operating range in voltage of the MAF.[/quote]

According to the service manual, the output of the MAF is a variable frequency, not a variable voltage. See the 3 attached PDF files (2 in this reply, 1 in next - tiny attachment size limit).

[Terry Kennedy]

3rd PDF:

[silver]

ok variable frequencies actually also work b/c the VC-MAF box my water injection came with does show voltage to frequency conversions, does the manual list the frequency range.

This would make sense why the voltmeter didn't really change upon hitting the gas BUT the water injection did turn on and gain in volume as I increased the throttle