Symtech FCD Calibration Help, FML!!! Options

[bsamps4]

Hey guys I just recently installed my symtech FCD, and thought that I was calibrating it properly, but after a few test drives this clearly wasn't the case. I had a situation where I leaned out under boost (I let off the gas immediately), and after some more adjustment all it would do is hit fuel cut. The adjustment screw on this thing will just spin and spin and spin in either direction (I was under the impression that it would stop at full left and full right rotation at some point). The green light on the device comes on in the same spot of the rotation every time, and then shuts off at the same rotation every time.

I ran a line from my compressor to the vacuum hose on my map sensor, and held it with 20 psi, but this thing is so finiky that I can't get the adjustment voltage right. AFter reading what other members have posted, I'm under the impression that I need to set the voltage between 4.10-4.17v. Do i actually need to blast the map sensor with 20 psi to do this? Or can I just turn the calibration knob and use a multimeter until is reads 4.10-4.17v?

Any help or tips would be appreciated. This thing is driving me insane.

[Batman722]

IIRC I had mine at 3.8ish.
You need the 20psi in there and use a multimeter. I used a bicycle pump when doing mine.