I am re-posting this under a different title to hopefully get a response.

In my first attempt to determine the duty cycle, I am following the article at:

http://www.landiss.com/mixture.htm

I have a CA 1990 300te.
Landiss indicates the following:

"For California cars, starting in 1988: Press the push button switch on test connector X92 (passenger side, between the two firewalls) for two to four seconds. The LED will flash once, indicating no fault code is stored in the system. Now press the switch again for two to four seconds. The LED will be on continuously, and the injection control is switched over to an on/off ratio output."

I am following the above procedure and each time I depress the button for 2-4 sec, I get 1 flash. I am unable to get the LED to stay on continuously.

Is this necessary to get an accurate duty cycle reading?
Any suggestions?