OK, what did I do wrong??

First of all, let me say that I have FINALLY learned the "If it ain't broke...DON'T FIX IT!!" rule.

My 1981 300tdt had a pretty rough idle when warm. Nothing major, but it bugs me. (i.e. "IT AIN'T BROKE")
I did several searches to see what there was out there, and the concensus was that I could easily remedy this by 'adjusting' the Rack Dampener.

So, I locate mine. 14mm hex and 12mm hex.
Here is what I did with the car idling:
1. Loosened the 14mm (set scerw?)
2. Tightened 12mm just about 1/4 turn.
3. Smiled from ear-to-ear as the engine settled right down (almost sounded like it was idling a little faster...) Almost didn't sound like a diesel!
4. Pulled on the linkage to see where she settled back down to and she stalled.
5. Started back up hard. I mean real hard as if it were 15 degrees out and no glow plugs working! (was actually about 70 degrees that day). Puffed HUGE clouds of black smoke.
6. Backed outta my garage to test drive and stalled when put into gear.
7. Restarted fine and continued my test drive to the corner about 100 yards when it stalled again.
8. Stalled at next stop light. (You get the picture?)

So I gave up and limped home where she stalled turning into my driveway. Loosened the 14mm again and loosened the 12mm to where *I thought* it was in the first place. Restarted the car and things were back to normal. *NOT*
The engine sounded just like it did b4 I messed with it in the first place, BUT it still kept stalling on me! !@#$!^$#@#

SO, I spent a ton of time this afternoon (instead of watching the NBA playoffs, argh...) turning the 12mm slightly back into place then taking her around the block, repeat several times and FINALLY think I have it back to normal which is rough idle but NO STALLING.

What the heck did I do wrong? I only turned the thing 1/4 turn?!?!

Any advice is appreciated as my wife is hesitant about driving it now.

__________________
Current: '91 300TE 4MATIC 317k and climbing...
Former:
'81 300TD Wagon 168K "Tank"
'83 240D 216K 4spd manual "Da Bear" (aka best car ever)

"Never sweat the petty things...
and never pet the sweaty things."