Advice needed for problem with '87 245 B230F (237,000 miles).
I have lived with an engine hesitation/miss just off of idle for over 40,000 miles, but lately the condition has worsened.

When pulling away from a stop or revving the engine in neutral, there is a slight cough right off of idle. It happens every time I open the throttle. Once moving, acceleration is smooth at all engine speeds.

However, in the last month or so, the car will start normally and as soon as I put it in gear, the idle drops and the car dies. This only happens when the engine is cold and it will always start right back up. It will die every morning when putting into gear unless I quickly put it back into park to increase the RPMs.

Overall performance is sluggish and the engine died once when braking hard for yellow light.

Here's What is New(er):
Spark Plugs, Wires, Cap & Rotor, Air & Fuel Filters, Fuel Pump Relay, Throttle Body Cleaned, Vacuum Lines OK

After reading a few posts, I'm suspecting something like the knock sensor or timing off. Any ideas?

Chris