I have had a problem with my ’84 733 (automatic) it has not run properly for over a year.

I have posted on every board I can find and e-mailed everyone I know. I have tried and tested a long list of possible causes and remedies and have zero results.

Here is a brief summary of what happened:
I have owned the car for many years. It has approximately 129 k miles and the engine has always run well. I was driving in town. The engine was warmed up and the car was driving and idling fine.
I stopped at a stop light. Just after the light the lane merges with another lane.
I accelerated hard to merge, probably in 2nd gear. The next light changed so I lifted off immediately. Sudden acceleration followed by sudden deceleration.
As I stopped at the light I noticed the idle extremely rough, the engine almost stalled. I managed to limp home. The symptoms are very rough idle, running way too rich, and will foul the plugs at idle.
The engine will start and it is possible to speed up the engine with no load. It sounds OK at about 2000 – 2200 RPM, smooth and spark plugs are clean. But I can’t speed up or slow down without it running very rough. Misfires and sometimes spits back through the intake.

1. Is it possible that the timing chain has jumped a tooth and my valve timing is incorrect?
Compression test is OK on all 6 cylinders.
2. Could the symptoms above be caused by incorrect valve timing?
3. Has anyone had this happen to a big 6?
I have owned several with a lot more miles and driven a lot harder than this one and never had a problem like this.
4. How can I check the valve timing?

I am most appreciative of all the help and advice from the forums but please note I have tried, tested and diagnosed a long list of possible causes for this problem and published most of the information on the forums. So far I have had zero results. What I am trying to do is establish if valve timing is the cause of my problem.

Thanks, John aka Kenneth
1984 733 129k
1991 735 IL 190K