190E fuel duty cycle measurements. Rich?

[ssanmor]

Hello all.
I have just tested the duty cycle measurement of the fuel injection in my 190E 2.3 8valve (1992).
When measuring with an oscilloscope between pin 2 and 3 (gnd in pin 2), I see the following:

Car warm, when contact on but engine stopping, fixed duty cycle around 30% (not sure of this).
When starting the car, it climbs to about 50% until the car warms up a bit.
Then starts oscillating a little bit. At idle, around 40-45% (time that the signal is 0V compared to the total cycle).

If I rev up the engine until, say, 2000-3000 rpm, the reading then drops to about 25%, oscillating a little bit (20%-30% or so). That's consistent if I hold the speed.

The temp of the engine was about 80deg.

Is the car running too rich? What is the expected effects of this? Can I adjust it just by turning the 3mm allen to the left a little bit?

I would like to hear your opinions because I would like to adjust it by myself.

I can post some photos if you need them.

Thanks in advance,
Sergio