i may be able to help but am confused why you're testing lambda with the car not running. lambda only really comes into play once the car is warmed up and in closed loop fuel control. with the car fully warmed up the oxygen sensor should be putting out a nice sine wave fluctuating between about 150mV to 850mV. you can get by with a nice DVOM but the ideal tool is a digital graphing multimeter or oscilloscope...

__________________
W108
W116
FJ60