I adjusted the spring tension on my 85 = GL Digijet 4 days ago.  The effect between spring tension and 02 sensor output = went backwards from what I expected.
 
 
I started with 1.37 AFM volts at idle. = I turned the notched black wheel in the AFM 10 notches clockwise, the AFM volts went = to 1.10. Which I expected.
 
But the 02 started at .75 volts open = loop, and after the spring tension adjustment the 02 went to .9 volts. Opposite of = what I expected.
 
So I moved the AFM tension to 10 = notches less than I had to begin with, the AFM volts went to 1.48. Which I = expected.
 
But now the 02 went to .7 volts, the = opposite of what it was supposed to do again.
 
The throttle valve controls the air to = the engine and I didn't change that, all I changed was the open loop AFM signal to = the ECU. With the greater AFM volts it should have added more fuel  not less.
 
I left it at the 10 notches less and = the .7 volts  02, and put it back in closed loop. The idle surge is gone = for now (usually happens on a warmer day anyhow) and the digitool is hooked up.
 
 
No I'm not crazy, or at least not since = I got out of my 20's.
 
 
Mark Ingalls