Well I decided since I was not getting results checking the duty cycle I would check the voltage between pins 3 and 2, it stayed right around 0.64 - 0.65! Then decided to check 02 voltage warm (since the car was already warm), and its putting out just over 0.9V! Turned it off for awhile started it back up and it was at .899. I will try it again tomorrow when the engine is cold. If I check the voltage between pins 3 and 2 with the O2 unplugged it right around .4 So either the system is running really really really rich (thought these only went from .02-.08) Or my O2 is faulty, what do you think?

I am going to hold off adjusting the air/fuel screw until I get an accurate duty cycle reading. I noticed my alternator is not putting out as much juice as it should, it's only maintaining 11.7 volts. Guess its time for a new alternator or voltage regulator. After I get the charging system back to what it should be I will go ahead and retest the O2 and duty cycle.

__________________
1983 240D 4spd
1984 190E 5spd
1987 300D (sitting for a year or two)
1989 Toyota Camry 5spd (current DD)

Very prudent approach!

Well I got the new alternator on, solid 14V current now. Still couldnt read the duty cycle, so I check the voltage on the O2 and it was still showing .9V. I decided to adjust the air/fuel mixture and lean it out a little. Went too far as the O2 voltage went and stayed between 0 and 0.1. Went a little rich and got the 3-7 fluctuation at idle I was looking for. Hooked up pins 3 and 2 and I got a voltage reading!! Calculated the duty cycle and it seems to stay between 45-50%. My idle is down to 700 rpms again, but the engine seems to be stumbling and running rough at idle. My vac gauge is not pegged in the black at idle, its about 35% of the way over towards the red, so I think I may have a vacuum leak. Would this cause a normal speed, but rough idle?

If so I checked all visible lines, and I cannot find any leaks. I hear the familiar leak sound from the front of the engine it sounds like it is coming from behind the power steering pump. Are there hidden vacuum connections under the intake? I was able to check all connections visible at the top of engine, as well as the distributor, charcoal canister and fuel pressure regulator and they are all fine. I am having a hard time finding an accurate diagram as my car is a 1984 (only year of the motor), and is a manual trans, which looks like that means less vacuum lines than other cars with an auto trans.

I think this has probably had the leak for some time, and the previous owner adjusted the air/fuel mixture all out of whack to try and correct it.

Also noticed my oil pressure is quite low when warm at actual idle, before when it was always idling at 1100-1300 rpms it would sit just below 2. Now at 700 rpms it sits right at 1 I'll changed to oil soon and see if it jumps up at all. Thanks for all of the help so far, could not have corrected this without

1. The help of this board
2. A multimeter
3. About 10 beers

__________________
1983 240D 4spd
1984 190E 5spd
1987 300D (sitting for a year or two)
1989 Toyota Camry 5spd (current DD)

If I were near you maybe I will share some of the 10 beer while helping you
Go to my stalling thread (do a search) on this forum and see if you missed anything. You may have to do an EHA adjustment to bring the fuel pressure to specs THEN do the air fuel mixture thingy.

After reading your post I think I am going to try that. Did your vacuum gauge move closer to the red at idle as well? I am quite sure the EHA has been adjusted before because you can tell the screw has been removed and reinstalled if you look at it carefully. I was hoping to avoid buying that Harbor Freight fuel injection system tester as I have spent close to $200 on tools between the 240D and 190 in the last month, but I guess it may come in handy again someday.

__________________
1983 240D 4spd
1984 190E 5spd
1987 300D (sitting for a year or two)
1989 Toyota Camry 5spd (current DD)